This is the roll center, suspension pickup, and steering angle modification thread. [Archive] - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

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PoorMans180SX

12-23-2009, 09:07 PM

Disclaimer: Modifying a car's suspension in the ways discussed in this thread will always result in some compromise. Increased steering angle makes things rub, raising the subframe increases anti-squat, etc. Please read through and understand the concepts before you go hacking up your car in pursuit of performance. All of the suspension components are affected when lowering the car, especially when lowered to the extreme. Correctly modifying the suspension pick up points or knuckles to correct for these changes can reap large rewards, including better camber and toe curves, less body roll for a given spring rate/anti-roll bar, and more traction/grip.

This thread is focused mainly on the S-chassis, with some Z and R chassis thrown in for good measure. There are many more brands than mentioned in this thread, but I've tried to include the most original and functional options. Feel free to contribute more.

Part I: The Basics.

The Front Suspension:

Tension rods: These are used to adjust caster, and together with the lower control arm pivot points, determine anti-dive and anti-lift in the front suspension. Positive caster like the S and Z chassis have gives positive steering feel, and helps the steering return to center automatically from lock. The angle of the tension rod and lca (horizontal plane, front to back) determines anti-dive under braking situations and anti-lift on acceleration.

Tip: If you're using your tension rods to adjust caster more than one or two degree(s) past factory settings, there will be bind in the lower control arm's traditional rubber or urethane bushing. It's recommended that you change to an aftermarket control arm with a heim joint/spherical bearing.

Front lower control arms: Determine your roll center (basically), track width, and camber curve of the front suspension. The arc they move in is the camber curve. Together with the tension rod they form an A-arm.

Tie rods are used to adjust the toe in the front, and obviously to steer your car. Aftermarket tie rod ends can be used to adjust bump steer by spacing the tie rod and changing its relationship with the control arm.

The Rear Suspension:
In a multi-link setup, as is present on nearly all modern RWD Nissans, the control arm pivot points determine the roll center, similar to a double wishbone setup, but with some variance according to where the toe and traction rod are mounted.

Rear upper control arms: Used to adjust static camber. Together with the lower control arm form the curve which the knuckle travels in vertically, gaining increasing negative camber with suspension compression.

Toe rods:These control static toe and toe change during suspension compression. When lowered aggressively, our car's toe and camber curves are significantly changed, becoming ‘steeper’ (more change with less movement).

Traction rods: Determine caster (or thrust angle) on the rear suspension. For most of us, that doesn't mean much. What matters is that they have a large effect on the toe curve, or bumpsteer of the rear suspension. A good rule of thumb is to lengthen these just as much as you lengthen your RUCA to minimize bump steer. This also slightly reduces anti-squat, which can be beneficial or detrimental depending on your chassis and setup.

Rear lower control arms: Help determine roll center, anti-squat, and camber gain. Can be used to adjust static camber as well as the camber curve over the suspension stroke.

Anti-squat: Anti-squat is probably the single most misunderstood aspect of the rear suspension. Anti-squat by definition is the resistance to squat the rear suspension possesses by way of diverting force through the suspension links. The higher the percentage the more resistance to suspension compression. Most people incorrectly assume that squat equals weight transfer to the rear, and thus increased traction. The truth is, multi-link rear suspension is vastly different from a solid axle, and squat actually reduces rear weight transfer, and takes up time compressing the suspension, where it must be damped by the shock. It is true that in traction limited scenarios, such as gravel or snow, we do want very little anti-squat, but on dry roads or the racetrack, this is not the case.
To determine anti-squat, we must first draw a line from the overall center of gravity of the vehicle through the centerline of the rear wheel. This is called the neutral line. Then we must draw lines from the rear control arm pivot points forward. Where these lines intersect, and whether they are above or below the neutral line, determines the percent of anti-squat. If they are below the neutral line, there is a negative percentage of anti-squat (or pro-squat), and if they are above there is a positive percentage. Around 120% is ideal. Here's a nice GIF and a couple images Motary put together.:

http://i.picasion.com/pic78/180a8b6ad7a4042a9bb95128e4d9f555.gif

Here's S14 anti-squat:

http://i.imgur.com/DL6YZmAh.jpg

And with GKtech rear knuckle:

http://i.imgur.com/T1k87Bwh.jpg

Unfortunately for 90's Nissans, we are stuck between two extremes. The S13 (and Z32/R32 for that matter), have a huge amount of anti-squat (somewhere around 180%), which means engine torque is very directly transferred to the tires, often shocking them into breaking traction earlier than ideal. The S14 and S15 (and R33/34), have a very small amount of anti-squat at standard height, but this quickly goes pro-squat when the car is lowered. This means the car squats excessively, changing the suspension geometry, reducing traction, and delaying the cars reaction to inputs to the throttle. Fortunately, the overwhelming aftermarket support for these vehicles have come up with some very nice solutions, which I will present below.

Roll Center:

Front roll center is determined by the angle of the lower control arms and the angle of the upper strut mounting points. These angles, drawn in space, determine the instant centers for the front suspension (instant centers are the points that the entire suspension moves around during body roll). Then take a line from each instant center to the middle of the tire tread on the opposite side, and where these lines intersect, there is your front roll center.

Rear roll center (for our cars) is determined much like a double wishbone setup. Use the angles of the upper and lower control arms to determine the instant centers of the suspension. Then, just like the front, take a line from each instant center to the middle of the tire tread on the opposite sides. The intersection is your rear roll center.

http://i.imgur.com/43UbNzH.jpg

Center of Gravity:

The center of gravity is the point at which all the weight of the car is balanced. It's roughly the crank centerline in the front, and above the differential in the back. You can find out your exact CG by using scales, but that is beyond the scope of this article.

Roll Couple:

Roll couple is the distance between your center of gravity and roll center. This is the reason that lowered cars have more body roll. The roll center moves lower (due to the change in angle of the suspension arms), while the center of gravity is only lowered as much as the body of the car. This makes the distance between the two longer, thus the roll couple longer, which gives the body more leverage on the suspension. I'm sure we all know how much of a difference leverage can make.

You actually want your roll center just under your center of gravity.

Part II: Roll Center Adjustment

Here are the things you can use to adjust roll center:

1. Use a ball joint with a shank that is longer, thereby spacing the pivot point at the knuckle farther down.

The only ball joints that I’ve seen that actually have a longer shank are Sunline Racing, Moonface, and Nagisa auto:

Nagisa:

http://i.imgur.com/gknIl76h.jpg

Beware of "Roll Center Adjusting ball joints" that just space the ball joint up. The ball joint shank needs to be longer. Nagisa has a good illustration (bad on the left, proper on the right):

http://i.imgur.com/8NPuGOn.jpg

The above method is only so effective. Due to the angle of the ball joint, using a long shank increases ackerman, and at about 20mm of correction, the lower control arm starts running into the brake rotor.

Dan at Parts Shop MAX made a nice diagram showing how the ackerman change happens:

http://i.imgur.com/rEKtKu1.jpg

2. Purchasing aftermarket lower control arms that have roll center adjusting heim joints and shanks.

There aren't a whole lot of arms that offer more than 10-15mm of correction because of brake rotor clearances. Ikeya Formula has some correction, and PSM has a 5mm fine adjustment spacer.

http://i.imgur.com/jA6QUDo.jpg

They've updated these with bent tension rods for more steering clearance:

http://i.imgur.com/BfX6e1Vh.jpg

PSM's limit break (longer) LCA:

http://i.imgur.com/DvZHFDQh.jpg

And GKTech's latest chromoly FLCA's. You can order these with 20mm longer shanks.:
(Image courtesy of swapmysilvia.com)
http://i.imgur.com/hXhWoPxh.jpg

These are some nicely engineered pieces, and they fail just as they should when running into things.

http://i.imgur.com/zeSmipJh.jpg

3. Modifying the pickup points on the knuckle (usually by creating a whole new knuckle), dropping them lower. Also, raising the hub location in the knuckle, which effectively creates a ‘drop knuckle’; a knuckle that lowers the car while keeping roll center similar. Some of the kits actually combine both ways, raising the hub, and lowering the pickup points.

Driftworks makes drop knuckles, 45mm in the front, and 50mm in the rear. The rears have urethane bushings for the control arms:

http://i.imgur.com/O02an4D.jpg

Stock knuckle:

http://i.imgur.com/eqvZy3G.jpg

Driftworks knuckle:

http://i.imgur.com/itWWEqv.jpg

R-chassis front Driftworks with 20mm correction:

http://i.imgur.com/lmJ3RcRh.jpg

They just released their new Geomaster V3, which was collaborated on with Wisefab. Now with 50mm of front correction and revised steering geometry. Front knuckle has drift and grip settings and the rear now has sphericals.

https://i.imgur.com/SDGKLLqh.jpg

https://i.imgur.com/YXRf8khh.jpg

http://i.imgur.com/8tBKroqh.jpg

Parts Shop MAX forged pro knuckle:

http://i.imgur.com/UtBLqJD.jpg

http://i.imgur.com/q39Rxb0.jpg

And their new ‘trailing knuckle’ with increased caster trail and adjustable ackerman:

http://i.imgur.com/npTJocTh.jpg

http://i.imgur.com/9lpH0kqh.jpg

Parts Shop MAX latest forged 25mm drop knuckle with spherical bushings:

http://i.imgur.com/RDquZbMh.jpg

And their ‘toe control’ brackets, which allow you to dial in different levels of bump steer:

http://i.imgur.com/6S6EpYbh.jpg

Here's a comparo shot between the Driftworks and PSM:

http://i.imgur.com/CD3V90E.jpg

Wisefab now has their s-chassis V2 kit out, packed with features. Double shear pickups for LCA and tie rod, camber/caster top hats, 56+mm of roll center correction, trailing knuckle design, adjustable ackerman, and a rack relocation kit that moves your rack 46mm forward.

https://i.imgur.com/HI5SWZ1h.jpg

https://i.imgur.com/5OnpxOZh.jpg

Wisefab's rear kit, with all new geometry for better rear grip:

https://i.imgur.com/jnCiMsRh.jpg

http://i.imgur.com/Eb0GpVR.jpg

GKTech now has three different variants of their front knuckle with 50mm of correction. They have grip, grip/drift, and pro drift versions, each with their own characteristics:

https://i.imgur.com/uKLRIqoh.jpg

http://i.imgur.com/ntkGBJjh.jpg

https://i.imgur.com/F0YLQbqh.jpg

They also have this cool diagram of the different steering geometries of their knuckles/kits:

https://i.imgur.com/6yZUQFyh.jpg

And this very informative link about all the geometry associated with their knuckle and why they designed it the way they did.

https://au.gktech.com/news/gktech-s-chassis-steering-knuckle

GKtech also offers R-chassis knuckles which can be used on the Z32.

http://i.imgur.com/lotcx0Wh.jpg

Photo courtesy of Chris York:

http://i.imgur.com/1RF83HIh.jpg

http://i.imgur.com/lqAEaroh.jpg

And their rear 40mm rear knuckle with new kinematics for better camber and to curves and corrected anti-squat. This knuckle is also significantly lighter than stock:

https://i.imgur.com/7d7aXY2h.jpg

https://i.imgur.com/jIH5f0Ih.jpg

http://i.imgur.com/EMttkf7.jpg

And GKtechs bolt on knuckle adapter with 40mm of correction (now in forged steel instead of aluminum):

https://i.imgur.com/RQNs2m5h.jpg

https://i.imgur.com/KMgG2vdh.jpg

Track Day Performance has a billet aluminum front suspension kit with 70 or 100mm of correction (No longer available).

http://i.imgur.com/0Er0Q4Ah.jpg

http://i.imgur.com/Nt7P9lJ.jpg

And their rear kit (I don't have shots of the arms that come with :()

http://i.imgur.com/FiHl3Mgh.jpg

Heatmaker knuckles offer 60mm of correction:

http://i.imgur.com/1Of94VFh.png

http://i.imgur.com/wJUJXhZh.jpg

6. You can move the whole subframe up, correcting the suspension geometry much like the modified knuckles.

SPL’s subframe adjusters (which can be either set for stock, or raised for ride height correction). These also can be ordered in an offset pattern, so you can mount a S14/15 subframe in your S13:

http://i.imgur.com/Ae4qunY.jpg

PSM's slip fit risers (Installing these was cake):

http://i.imgur.com/VGTGHNrh.jpg

NOTE: Raising the subframe also increases anti-squat. SPL provides a very good link on how pushing the Subframe affects anti-squat and roll center:

http://splparts.com/instructions/SPL_SSB_S13C.pdf

PoorMans180SX

12-23-2009, 09:08 PM

Part III: Steering Angle Modification

Let's talk about steering geometry for a bit. There's a lot to consider when you're picking out parts for steering angle. We now have tons of options. When I first made this thread, it was pretty much cut n' shut knuckles or Driftworks.

Ackerman in the steering:

In layman's terms, ackerman is the steering angle difference between the right and left front wheels when turned. This has important implications in drifting and in road course work. When turning normally, the wheel to the inside of the corner turns a smaller circle than the outside one. This makes the ideal angle between the two different. In long sweeping corners, low ackerman is advantageous, while tight hairpins require more positive ackerman. Drifting has the same requirements, except there are situations where you are turning much farther than a road course car would be. Too much ackerman in high speed corners (or at high steering angles) means that the wheel with less angle is scrubbing, which slows the car down and increases tire wear. Too little ackerman in tight corners means the opposite, while turn-in speed is reduced and more input required.

Basic image of ackerman reduction:

https://i.imgur.com/6pTVip1.jpg

Now let's talk about steering axis inclination (SAI). This is also known as kingpin inclination or kpi, but since cars haven't had kingpins since the 30's, I feel like we should use the proper term. This is another thing that is very easily misunderstood, as the kinematics are quite dynamic throughout the steering range.
For the purpose of our discussion, I'm going to talk about SAI as if it includes caster. By definition SAI is the angle of the suspension from the top mount of the shock through the ball joint when viewed from the front only, but since our cars are always going to have positive caster and our goal is to understand how the suspension angle effects the geometry throughout steering lock, it's easier to condense the two.
Let's start with a car going around a track in standard racing fashion. Front camber while steering is determined by the SAI, and with positive caster, this means the outside wheel gains negative camber and the inside one positive. This is very beneficial in typical racing, as the outside wheel needs negative camber to offset body roll and tire deflection. This can obviously be adjusted so as to be optimal per setup. In drifting, quite the opposite is true. Countersteering into a corner means the lead wheel gains positive camber and the trailing negative, leaning the tires up on their edges and reducing contact patch. This effect also makes the steering want to self-center, as the car lifts in the front and the weight of the car wants to push the steering back to center. There is a balance to be struck here, and it largely depends on how the driver likes it. Professional drifting has moved towards reduced caster and therefore flatter contact patch at big steering angles. This increases controllability at speed and allows for effective braking. A large number of grassroots drivers prefer standard or even increased caster though, this makes the car self-steer more aggressively, and can help with hucking big backwards entries. The front tires will start to slide and then smoothly return when correcting, which makes the entry look much smoother.

Caster trail:

There is also ‘caster trail’ to consider. With the need for larger front contact patches and less static caster, the steering can lack feel and lead to a driver having to steer excessively, pulling the wheels away from lock and manually returning the wheels to center. By setting the hub farther back in the knuckle (front to rear), the caster trail can be increased, meaning that the steering still wants to return to center even at low static caster angles. I borrowed this image from interia-ms.com as it illustrates it nicely:

http://i.imgur.com/uKYntcYh.jpg

PSM, Wisefab, and TDP, and Driftworks all have knuckles with increased caster trail available. GKtech has one in development. PSM has a good side-by-side so you can see the difference. Trailing knuckle on the left and standard on the right.

http://i.imgur.com/GrgfMRUh.jpg

With the increased prevalence of reducing static caster angles, companies have developed offset strut tops. This allows the tension rod to be used as a fine adjustment, and keeps the wheel more centered in the well.

GKtech has two versions, one that you need to cut the top of the tower to fully utilize, and another thicker one that bolts in with no modification:

http://i.imgur.com/M66xa1Dh.jpg

http://i.imgur.com/shUKHbJh.jpg

TDP's is similar to the second GKtech:

http://i.imgur.com/UjWJYEzh.jpg

PSM has one available for their coilovers specifically:

http://i.imgur.com/dcuWD92h.jpg

Wisefab was pretty much the originator of the idea, first with their fixed position "non-FD legal" tops, and then with their adjustable "FD legal" variant. Fixed position is pictured above in the picture of the full kit.

http://i.imgur.com/WPjR540h.jpg

There are several ways to go about getting more steering angle; like tie rod spacers, steering rack spacers, and obviously modified or new knuckles.

Classic steering angle spacer:

https://i.imgur.com/tByWkxb.jpg

Big steering angle spacer:

https://i.imgur.com/eJJEeOF.jpg

There have been plenty of companies that have come and gone over the years, making their own version of modified or new knuckles for the s-chassis:

Naoki Nakamura's now infamous B-knuckle:

https://i.imgur.com/vUQSu2kh.jpg

https://i.imgur.com/3qvz7q9h.jpg

MA-Motorsports modded (no longer available):

https://i.imgur.com/5mt8vKh.jpg

Billspeer 555 Knuckle (no longer available):

http://i.imgur.com/maPJBZgh.jpg

Abercrombie (no longer available):

http://i.imgur.com/KoHMLz2h.jpg

http://i.imgur.com/3NM6TSnh.jpg

Driftworks claims 65 degrees of steering lock on their V2 Geomasters:

http://i.imgur.com/lhMRWPUh.jpg

http://i.imgur.com/COcRIAuh.jpg

Parts Shop MAX has 65+ degrees of steering lock:

http://i.imgur.com/v3PisZmh.jpg

http://i.imgur.com/6IO9NKMh.jpg

Wisefab also claims 65 degrees of lock:

http://i.imgur.com/glU5O6Wh.jpg

And their ackerman adjustment spacers:

http://i.imgur.com/K1Qw7xNh.jpg

Track Day Performance claims up to 70 degrees of lock (No longer available):

http://i.imgur.com/zqjDCVbh.jpg

GKtech claims 70 degrees of lock with their V3 knuckles and LCA combo:

http://i.imgur.com/b73LG1vh.jpg

Overcentering:

Another thing that's rarely mentioned when talking about all this increased angle, is the tendency of the steering rack to go "over center". This is where the angle of the tie moves farther than parallel with the steering arm of the knuckle Image borrowed from interia-ms.com

http://i.imgur.com/5VJoEzsh.jpg

This can be alleviated a couple ways:

1. Moving the steering rack forward:

https://i.imgur.com/B9Wm400.jpg

https://i.imgur.com/qB0K1dW.jpg

2. Spacing the tie rods farther forward, using spacers like these Driftworks ones:

Version 2:

https://i.imgur.com/OQfOEJQ.jpg

Or the Parts Shop MAX version:

https://i.imgur.com/0jynKz0.jpg

and GKTech:

https://i.imgur.com/5vXBK1v.jpg

These do the same thing as the eccentric bushings, but have more correction. And there have been talks of solid steering rack bushings warping and becoming loose.

NOTE: These could put stress on your rack that it was not designed for.

3. Using Parts Shop MAX steering rack eccentric bushings:

https://i.imgur.com/O9XRLv0.jpg

https://i.imgur.com/M0ZxPPC.jpg

Dan gathered some interesting information about how moving the rack forward effects ackerman angle:

https://i.imgur.com/dWWwvBr.jpg

4. Once you're using high-clearance tension rods/control arms, you'll need to worry about your trailing wheel hitting your sway bar. There are two solutions for this:

The GKTech high clearance sway bar:

https://i.imgur.com/nzDXLxmh.jpg

https://i.imgur.com/Eka1Auvh.png

https://i.imgur.com/KlFpaMah.jpg

And the Bink Industries high clearance bar, available in street and Pro versions, and residing on quite a few Pro and Pro-am cars. These come with endlinks, D-bushes, and brackets.

Street:

https://i.imgur.com/rgmNkORh.jpg

https://i.imgur.com/W4iFOlYh.jpg

https://i.imgur.com/FA27LpGh.jpg

Pro:

https://i.imgur.com/lVLvKOYh.jpg

https://i.imgur.com/Jy9QEKbh.jpg

https://i.imgur.com/W0HAji7h.jpg

Parts Shop Max has a high-angle sway bar as well. Comes with brackets, bushings, and locks.

https://i.imgur.com/xBvBZpih.jpg

https://i.imgur.com/OR1Y89xh.jpg

Depending on your knuckle/LCA/tie rod end combo, you're probably going to need longer tie rods. Here's a nice list of lengths:

Inner:
M12x1.25:
11.10" - '89-'94 240sx (S13)
M14x1.5:
11.37" - '95-'98 240sx (S14)
11.42" - '94-'99 Maxima (A32)
11.42" - '96-'99 I30 (A32)
12.00" - '97-'01 Q45 (FY33)
12.00" - '01-'06 Q45 (F50)
12.91" - '99-'03 Maxima (A33)
12.91" - '00-'04 I30 (A33)
13.30" - '03-'08 Maxima (A34)
9.25" - PSM Short
11.73" - PSM Medium
13.93" - PSM Long
14.50" - GKTech

Outer:
M12x1.25:
3.88" - '89-'94 240sx (S13)
M14x1.5:
3.63" - '95-'98 240sx (S14)
5.00" - '88-'94 Maxima (J30)
x.xx" - '94-'99 Maxima (A32)

Let's discuss.

sincity_sil80

12-23-2009, 09:56 PM

wow looks like you put a lot of work into getting this thread started. very informative. good job imo

hotlavaflow

12-23-2009, 10:13 PM

In for info and updates I like where this thread is going

Shadowhunter

12-23-2009, 10:21 PM

Great job and good info, thanks for taking the time to do this.

Teknolust72

12-23-2009, 10:28 PM

Awesome info!!! Thanks!!

PoorMans180SX

12-23-2009, 10:33 PM

You're welcome guys. This is something I kind of geek out on, so I thought I would contribute to the community.

Here's a question I have.

It seems like if you did all the roll center adjustment you possibly could, you could actually put the roll center above stock, even on a slammed car. Anyone know if this is detrimental to suspension performance or not? Maybe it's advantageous?

ManoNegra

12-23-2009, 10:54 PM

theslows13

12-23-2009, 10:56 PM

i <3 this thread :D

i own the PSM subframe risers and knuckle/LCA kit. complimented by the rest of their GEN1 catalog lol....

i want MOAR now

roboticnissan

12-23-2009, 11:28 PM

im really sure there is a ton of info here but im an uber noob on suspension and dont really nkow whats going on in some of these pictures. maybe a introductory thread that leads up to this one would be sweet!!

PoorMans180SX

12-24-2009, 12:57 AM

There various thread on NRR already dealing with these topics
one of the more extensive ones:

Roll Center.....again - Nissan Road Racing Forums (http://nissanroadracing.com/showthread.php?t=669&highlight=roll+center)

good topic, I've seen the suspension set up of a Porsche GT3 Cup car and it floored me
just like our cars they're McPherson struts up front with a independent arms in the rear
I want that in my car

That's nice, but THIS IS ZILVIAAAAA!!! haha. I wanted a thread on here, and I want to update it with the latest products and such, not just "this is how you could possibly do it". Thanks for a solid link though, I might steal some of their pics to make this thread better.

im really sure there is a ton of info here but im an uber noob on suspension and dont really nkow whats going on in some of these pictures. maybe a introductory thread that leads up to this one would be sweet!!

Yeah, I might do that, but most of the general stuff is readily available and easy to find. This is the hardcore stuff.

95KA-Turbo

12-24-2009, 01:22 AM

There various thread on NRR already dealing with these topics
one of the more extensive ones:

Roll Center.....again - Nissan Road Racing Forums (http://nissanroadracing.com/showthread.php?t=669&highlight=roll+center)

good topic, I've seen the suspension set up of a Porsche GT3 Cup car and it floored me
just like our cars they're McPherson struts up front with a independent arms in the rear
I want that in my car

That's my thread on NRR - lots of ideas got shot down in there, haha.

One of them was modifying the inner pick up point. You affect a lot more then just the roll center when you do it. There is more then enough room to drill a hole above the stock location and move the arm up a good inch. I was steered away from that by the guys on NRR though so I would listen to them.

Also, my rear arms are corrected more then stock, I just don't have any spacers on them yet. You can see the slight angle difference from my toe arm and LCA. I should be able to get it mostly flat, but I've got to track down the proper spacers.

Also, you don't necessarily want the roll center back to the factory location. The 240 wasn't exactly a performance monster from the factory. I haven't done enough research to say what might be optimal...so going for straight LCAs is a good goal for now. I'll be able to fine tune it as I drive it.

om3ga

12-24-2009, 01:32 AM

Oh wow this thread has definitely been one ive been waiting for/ planning to make. Ive been researching this stuff forever too but it seems like you have covered a lot of it! NICE JOB!

ballinnmiami240sx

12-24-2009, 05:45 AM

I did all the mods to 95KA-turbo's suspension. Let me tell you that this wont be an easy install. All the parts that where ordered had very close tolerences. I had to grind down/sand a few things to get it to work. We dont now how its all gonna work out because we are in the R&D mode right now. Once we get it set the way we want it we will report back here with updates. Hope fully in about 2 months when the car is rolling under its own power.

Danny

Jonnie Fraz

12-24-2009, 08:06 AM

Very informative! Thank you very much for putting this together.
I am interested to see how these mods are affected by the sactioning bodies. Last I read is that you could only move your pick up points 1" in any given direction.

ManoNegra

12-24-2009, 08:30 AM

Otto347

12-24-2009, 09:23 AM

I modified the stock lowers (rear and front) to acccept 3/4" spherical bearings and monoball studs for roll center adjustment. No pics of the fronts yet. But I had to ream the uprights to a 7° GM taper for the studs to work.

http://otto-fab.com/pics/IMG00080-20091007-1646RCA_mod2.jpg

http://otto-fab.com/pics/IMG00106-20091025-1544_rolladj.jpg

Otto347

12-24-2009, 09:30 AM

I don't see how this would affect more than the roll center. There is no real camber curve to a McPherson front suspension other than the arc of the front control arm, and toe is controlled by the tension rods, which remain in the same place. Maybe if you had stock tension rods. I guess I'll have to look through that thread.
Tension arms control caster, unless you are talking about the tie rods.

95KA-Turbo

12-24-2009, 09:44 AM

Tension arms control caster, unless you are talking about the tie rods.

I am sure it was a simple slip up in typing, but yes that's important to point out, haha.

I personally do not 100% understand how moving the inner point up effects the motion of the tension rod - I mean it should technically do the same thing as lowering the outside out point. I was assured that it would put some unforeseen forces on the arm that would screw up everything. I am not an engineer - perhaps Def will come in and explain. It is stated in that NRR thread. I got mad because no one would explain it to me at first, then I got a kind of half-ass explanation from a few people.

SoSideways

12-24-2009, 09:46 AM

Tension arms control caster, unless you are talking about the tie rods.

That is correct.

And therein lies the problem, if you move the FLCA pickup points up, because the rack would also need to go up along with the FLCA pickup points so that the tie rods' arc and the FLCAs' arc will stay in sync.

If not, the car will get some nasty bumpsteer. that pretty much cannot be corrected due to the 2 having totally different arcs.

Edit - if you move the FLCAs' pickup point, then the T/C rods' pickup points will have to move up the same amount as well.

Think about it.

If you moved the FLCAs' pickup points by an inch, and if you flattened it, the T/C rods will no longer be parallel to the FLCAs anymore. They'd be pointing up in order to meet the FLCAs, and probably no way for them to bolt up to the FLCAs because of the angle that they're in, so they will need to be moved up an inch as well.

Otto347

12-24-2009, 10:01 AM

If not, the car will get some nasty bumpsteer. that pretty much cannot be corrected due to the 2 having totally different arcs.
Well corrected to a point with a bumpsteer kit but they can only correct so much before moving the whole rack up is the next option. Which in my case with the LSx is a no go, there is about 1/16" between the rack and the oilpan.

ManoNegra

12-24-2009, 10:11 AM

If you moved the FLCAs' pickup points by an inch, and if you flattened it, the T/C rods will no longer be parallel to the FLCAs anymore. They'd be pointing up in order to meet the FLCAs, and probably no way for them to bolt up to the FLCAs because of the angle that they're in, so they will need to be moved up an inch as well.

Exactly, I liked the solution on the Porsche cup car
the traction rod connects to a perpendicular brackets and it's position can be adjusted with round spacers of various lengths held with a bolt
the lower control arm is a two piece design cast in aluminum - shims can be stacked near the crossmember bushing held by two bolts to adjust track and probably quick alignment changes.

95KA-Turbo

12-24-2009, 10:12 AM

Ah that's right, it makes sense to me again. I had forgotten how I had to think of it to make sense, haha.

By moving the inner point up, you are making the LCA angle better but the tension rod angle worse. By moving the outer point down you are making your tension rod angle and LCA angle better at the same time. The tie rod angle can be fixed with spacers and heim joints, much like the spherical bearings and spacers used for the roll center.

Here is an interesting article that somewhat explains why one type of roll center isn't ideal for everyone/every car. Unfortunately they're talking about stock cars and they have completely different suspension set ups then we do:

Accelerating Performance: Roll Center Magic (http://acceleratingperformance.blogspot.com/2009/11/roll-center-magic.html)

SoSideways

12-24-2009, 10:14 AM

The point is, the tie rods' pick up point will differ from the FLCAs' pick up point if you move just the FLCAs. One will be higher than the other, which will cause different arcs.

When 2 arms have the same arc, you can correct for stuff much easier.

When you have 2 arms that have different arcs now, it is much harder to correct for that type of stuff....

GSXRJJordan

12-24-2009, 10:43 AM

ManoNegra

12-24-2009, 11:33 AM

Loving this thread, and the work that went into making it. True, this is more of a NRR-type thread (that site is awesome, btw, I just got turned on to it recently), but I love that the community is moving towards real performance modification, not just 'this looks cool', or 'check out what i did for free'.

Makes me proud :)

Luke (Blu808) and I have been talking over making some CNC aluminium LCA's since we both have access to CNC machines and I have all the heim joints. We just need to come up with a final design (which has to address roll center, bump steer if possible, big angle kits, etc) ~ maybe this thread will help.

agree, I'm interested in what you and Luke will come up with
we're in a similar situation, we can make just about anything but it's not very useful without a well thought out design
any automotive/mechanical engineers in socal that are serious about making cool shit, get at me :mepoke:

S14DB

12-24-2009, 11:42 AM

That's my thread on NRR - lots of ideas got shot down in there, haha.

One of them was modifying the inner pick up point. You affect a lot more then just the roll center when you do it. There is more then enough room to drill a hole above the stock location and move the arm up a good inch. I was steered away from that by the guys on NRR though so I would listen to them.

Also, my rear arms are corrected more then stock, I just don't have any spacers on them yet. You can see the slight angle difference from my toe arm and LCA. I should be able to get it mostly flat, but I've got to track down the proper spacers.

Also, you don't necessarily want the roll center back to the factory location. The 240 wasn't exactly a performance monster from the factory. I haven't done enough research to say what might be optimal...so going for straight LCAs is a good goal for now. I'll be able to fine tune it as I drive it.
I liked this idea:
http://http://i25.photobucket.com/albums/c51/95KA-Turbo/rollcenter5.jpg

It's what silk road does on their time attack car. I wish I had more data on it but have only seen one article.

udon!

12-24-2009, 11:42 AM

wow, nice thread, you saved myself the embarrassment of making a n00b ver. of this thread. lol.

this is complicated. but it shows the importance of all the arms

mmdb

12-24-2009, 12:39 PM

Loving this thread, and the work that went into making it. True, this is more of a NRR-type thread (that site is awesome, btw, I just got turned on to it recently), but I love that the community is moving towards real performance modification, not just 'this looks cool', or 'check out what i did for free'.

Makes me proud :)

Luke (Blu808) and I have been talking over making some CNC aluminium LCA's since we both have access to CNC machines and I have all the heim joints. We just need to come up with a final design (which has to address roll center, bump steer if possible, big angle kits, etc) ~ maybe this thread will help.

In respect to rear roll center adjustment, would you guys be making a set of rear spindles with the option of using spherical inserts and a z32 for type mount for the struts? I'd like to be able to use my z32 rear e-brake assembly as well.

To add to this thread, adding additional roll center adjustment for the rear (ie lower control arm) could possible hurt the rear geometry of the other arms. The best fix would be to replace the rear spindle to ensure that the arc movements remain unaltered.

95KA-Turbo

12-24-2009, 12:54 PM

Definitely, a new spindle out all around is by far the best method to correct everything properly. An adjustable control arm on top of that would be great, then EVERYTHING could be adjusted.

PerilousActs

12-24-2009, 12:59 PM

Glad I found this thread. I've been trying to learn more about suspension lately. In for updates.

RHD95S14

12-24-2009, 01:00 PM

Has/does anyone notch the front spindle for more camber gain?

I've done this on several dirt "factory stocks" and it seems to work quite well.

Subscribed.

GSXRJJordan

12-24-2009, 01:56 PM

In respect to rear roll center adjustment, would you guys be making a set of rear spindles with the option of using spherical inserts and a z32 for type mount for the struts? I'd like to be able to use my z32 rear e-brake assembly as well.

To add to this thread, adding additional roll center adjustment for the rear (ie lower control arm) could possible hurt the rear geometry of the other arms. The best fix would be to replace the rear spindle to ensure that the arc movements remain unaltered.

I have no idea what to do with the rear. I'd love to do a heim on the front with the ability to raise/adjust the rear pivot point (for squat), but I can't think of a nice way to do it.

Definitely, a new spindle out all around is by far the best method to correct everything properly. An adjustable control arm on top of that would be great, then EVERYTHING could be adjusted.

Spindles would be do-able as well, but that's a whole 'nother headache lol. I agree that's the best way to go.

Coolest things about all of this is:
a) Aluminum is cheap
b) CNC time is reasonably cheap
c) heims/bearings are cheap
d) Lots of engineers have S-chassis cars

PoorMans180SX

12-24-2009, 02:04 PM

That is correct.

And therein lies the problem, if you move the FLCA pickup points up, because the rack would also need to go up along with the FLCA pickup points so that the tie rods' arc and the FLCAs' arc will stay in sync.

If not, the car will get some nasty bumpsteer. that pretty much cannot be corrected due to the 2 having totally different arcs.

Edit - if you move the FLCAs' pickup point, then the T/C rods' pickup points will have to move up the same amount as well.

Think about it.

If you moved the FLCAs' pickup points by an inch, and if you flattened it, the T/C rods will no longer be parallel to the FLCAs anymore. They'd be pointing up in order to meet the FLCAs, and probably no way for them to bolt up to the FLCAs because of the angle that they're in, so they will need to be moved up an inch as well.

What you're saying about moving the inner FLCA pickup point up totally makes sense now. I've edited the thread to show it. However, The tension rods don't really have to be moved. Just look at Matt Powers car. His tension rods are pointed up.

And I'm not convinced about the rear at all. Moving the rear pickup point doesn't put it out of sync with the rest, as they all move the same way. And the Parts Shop MAX car has used this method with success.

SoSideways

12-24-2009, 02:23 PM

95KA-Turbo

12-24-2009, 02:57 PM

Yes, Matt's tension rods are pointing up, and if he raised his inner pickup point they would be even more deformed. The point is to get ALL suspension geometry correct while having the car retardedly low - at least that's the point I'm going for.

Its counter productive to do something that requires extra steps for no reason. Moving the inner point up 1" like Formula-D allows will not correct the roll center enough, so you'll still need to change the spindle or LCA.

KoukiMonsta

12-24-2009, 03:10 PM

this thread is fucking legit

ballinnmiami240sx

12-24-2009, 03:18 PM

A set of knuckles wont be any help if you cannot correct the angle of the LCA at a given ride height. This means that the only solution to this would be a set of 2 piece spindles that can be taken apart to install a roll center spacer. One of the J-land companies has these.

Otto347

12-24-2009, 03:52 PM

^^Or raising the pivot points on the crossmember, wont happen with stock control arms but if you are running heims there is room for moving the mounting hole up 15mm.

Edit: but now that I think about it the swing arc on the tension arms is still going to be messed up. I guess you could achive the same thing with adjustable ball joint studs but youre still left with the steering arms. Do the J-land spindles raise the roll without messing with the steering arms?

SoSideways

12-24-2009, 05:17 PM

The J-Land one is the GP Sports knuckles.

There are two versions.

One version has a fixed 20mm or something adjustment plus added angle at full lock.

The adjustable one can be spaced with spaces that will space both the tie rod end mounts and ball joint mounts together as one unit.

95KA-Turbo

12-24-2009, 06:04 PM

Ideally you would have an adjustable LCA with a spindle that corrects geometry, so you can fine tune it with the LCA and the knuckles could adjust like 30mms or so.

A way to bypass the whole tension rod issue is to get rid of the 2 prong bolt on method and make a LCA with a bracket to allow a double heim joint tension rod. So you can weld it on however higher or lower depending on what you do with the inner LCA pick up point.

Something similar to this:

http://www.e30m3project.com/e30m3performance/installs/installs-3/control_arms/pic-2.jpg

A company called SP-Tec in Japan makes these:

http://sp-tec.com/shop/goods_image/A28_Z1.jpg

http://sp-tec.com/shop/goods_image/A29_Z1.jpg

mothon

12-24-2009, 08:41 PM

Nice thread.

What do you guys think about the new driftworks spindles?

Def

12-24-2009, 09:16 PM

True.

The FLCAs do have enough flex in the inner bushing for it to be tilted forward and still work to a degree, but you'd sacrifice the range of motion that the ball joint or spherical bearing will have on the outer end due to the FLCAs now having a slanted angle.

Even with Def's modified Godspeed FLCAs, his spherical bearings (that replaced the ball joints) only has 15 degrees of misalignment on it. While he will probably never use the full range of 15 degrees, if your arms are tilted down in the front due to the T/C rods not being relocated as well, then the misalignment angles decrease, and you might run into problems then.

All hypothetical of course, but still, if I were to mess with the suspension, I'd rather do it right and make sure things aren't going to go out of whack, instead of just going by the "eh... it's good enough" approach.

Stock front balljoints have about the same amount of articulation. Can't remember if I said it was about 15 degrees each way, but it's probably a bit more that that. Maybe 20 degrees each way. Regardless of the amount, it is not far off a stock balljoint.

Correcting the front roll center brings the front tension rods to about the stock angle. Not sure why you guys are stressing out about the front tension rod, as any higher you make the front roll center.

mothon

12-24-2009, 09:46 PM

Are any of you guys that are running a lot of caster having any issues with the tie rods binding?

PoorMans180SX

12-24-2009, 10:18 PM

95KA-turbo, that tension rod setup makes sense! Thanks! It looks like the Ikeya Formula arms, just more basic. But you could definitely adjust tension rod position if you made them yourself.

Also those knuckles look crazy similar to the Driftworks ones. Right down to the bushings, haha.

So here's a thought;

Say you have PSM knuckles, which already correct for bump steer. Then you get SPL tie rod ends, which have spacers to correct for bumpsteer. Third, you move the inner pivot point of the control arm up and install SPL's spacers to space the tie rod down even farther. Wouldn't this make the tie rods parallel to the new control arm location?

I know it's kind of a drastic amount of adjustment, but it should work.

I wanted to draw this in paint, but I can't find a good picture to do it with.

You can move the tension rods up a little bit, seeing as with decently high spring rates they don't move up and down a whole lot. Also, what about mounting the tension rod to the bottom of the control arm instead of the top?

And no one has any idea of where you actually want your roll center? To me, stock makes sense. All of my ideas won't really matter if it's ideal to have your roll center farther down than stock, as you won't need such drastic adjustment, hahaha.

BTW, thanks for all the input and compliments guys, I'm really enjoying this thread!

Def

12-24-2009, 11:03 PM

You can get the roll center up close to your CG without moving the inner pivot of the FLCA, so no idea why you'd consider that.

You don't really want your roll center right at your CG height either, as it can create weird handling as it moves from very close to your CG to far away upon corner entry.

PoorMans180SX

12-25-2009, 12:51 AM

nieko

12-25-2009, 12:59 PM

Keep this thread going, shit is great.

I have the SPL tie rod ends and it lowers the tie rods a BUNCH. but i feel like the control arms need to be moved still..

This is kind of irrelevant but, when i reverse out of say a parking spot and i hit full lock, i cant turn the wheel the opposite way right away, its ilke completely locked until it moves forward a bit.

I dont have this problem while drifting or any other type of driving, only when reversing.

I know this shouldnt be happening...

Def

12-25-2009, 07:28 PM

AH! This makes sense. I'm guessing the center of gravity in the 240SX is farily low? Say, just about seat (butt) level?

I knew there must be some reason no one was doing those kind of crazy modifications.

Front CG in ours cars is probably just above the crank centerline, give or take a couple of inches. It doesn't take too much outside pivot lowering to at least get close to there.

PoorMans180SX

12-25-2009, 08:26 PM

Front CG in ours cars is probably just above the crank centerline, give or take a couple of inches. It doesn't take too much outside pivot lowering to at least get close to there.

Wow, yeah, that's not high at all. Thanks so much for the info, I'll edit the original post to reflect this.

A set of knuckles wont be any help if you cannot correct the angle of the LCA at a given ride height. This means that the only solution to this would be a set of 2 piece spindles that can be taken apart to install a roll center spacer. One of the J-land companies has these.

It was GP Sports. They no longer make them for the S-chassis.

nathanong87

12-26-2009, 03:58 PM

awesome thread. learned something new!

240sxaddict

12-27-2009, 11:45 AM

PoorMans180SX

12-27-2009, 01:16 PM

I never quite understood adjusting squat/anti-squat. I know you can angle the rear subframe and/or lower control arm, but which way to reduce anti-squat?

And i've heard good things about doing that in S13 drifting applications, is it really that noticeable/wanted of a change? People aren't very specific when it comes to talking about the after-effects.

Basically you want to "flatten" the lower control arm. Usually by moving the back pickup point up.

Basically it gives you more weight transfer to the rear, more "squat", and better traction when accelerating hard. This really helps for higher-powered cars that have problems putting the power down.

Omarius Maximus

12-28-2009, 07:06 AM

This thread assumes that people actually have suspension travel. That's a pretty big assumption on Zilvia.

BlitzRPS13

12-28-2009, 08:26 AM

Nice thread... i have also zero suspension travel.. i just hop down the road.

rb26man

12-28-2009, 08:37 AM

what would be a good daily and track suspension set up...im currently running apexi n1 coilovers but i may sale and buy dmax coils lmk

95KA-Turbo

12-28-2009, 08:51 AM

This is not really the thread for that...there were like 6 threads made in the past month about coilover choices in general discussion. I personally love the Fortune Auto coilovers on my car though.

PoorMans180SX

12-28-2009, 01:44 PM

Yeah, let's try to keep it on topic people.

No coilover talk please.

mmdb

12-28-2009, 02:16 PM

Just to add some FYI stuff, I'm running the GP Sports Hyper Knuckle (Adjustable). I originally had a 20mm spacer in there in additional to the 15mm? that the knuckle added and it was a bit TOO much roll center adjustment causing major understeering issues. This is due to the front vs rear roll center, or in other words the front roll center was far too high compared to the rear, which doesn't allow the car to rotate. So without much, or any rear roll center adjustment, adding a crap load of front roll center adjustment will hurt performance. So if you're interested the GP Sports knuckle, or any sort of front roll center adjustment is fine. Ultimately, there needs to be an effective rear roll center adjustment to balance the car. The Driftworks option posted on page one looks like the best option, though I'd like to know if it can be used with a z32 brake setup.

http://i7.photobucket.com/albums/y259/mmdb/Misc/IMG_0663.jpg

ballinnmiami240sx

12-28-2009, 02:31 PM

My next question......

Could we technically split in half a set of knuckles and build the bottom half out of 6160 aluminum? I have been wanting to do this for a while now. I threw this idea around the shop and Im gonna talk to my machine shop to see what he can come up with.

racepar1

12-28-2009, 03:11 PM

I have some concerns about adjusting the rear roll center by simply spacing the joint down. The balljoints are mounted at an angle. That means that if you simply space the joint down you end up with a longer lower control arm to put the upright in the same position. Since the rear is a multilink that could affect the camber and toe curves. The affect could, of course potentially be positive or negative, but negative is much more likely. IMO in the rear the way to go is to re-locate the subframe and modify the spindles.

PoorMans180SX

12-28-2009, 04:00 PM

The Driftworks option posted on page one looks like the best option, though I'd like to know if it can be used with a z32 brake setup.

http://i7.photobucket.com/albums/y259/mmdb/Misc/IMG_0663.jpg

Man, it's too bad GP Sports stopped making those for the S-chassis.

Supposedly you can use the Driftworks knuckles with the Z32 rear brakes, but they require "modifications" to fit.

I have some concerns about adjusting the rear roll center by simply spacing the joint down. The balljoints are mounted at an angle. That means that if you simply space the joint down you end up with a longer lower control arm to put the upright in the same position. Since the rear is a multilink that could affect the camber and toe curves. The affect could, of course potentially be positive or negative, but negative is much more likely. IMO in the rear the way to go is to re-locate the subframe and modify the spindles.

Are you talking about using a longer ball joint/shank in the lower control arm? This would affect the suspension curves, but really the affect would not be large.

Most roll center adjusting control arms/ball joints only move the pivot point down by 15mm or so and that 15mm only increases control arm length probably 5mm effectively, which should be able to be offset by the adjustment of the inner heim joints if you have an adjustable arm. And if not, just adjust all your other arms 5mm longer.

95KA-Turbo

12-28-2009, 04:52 PM

He's talking about the actual arcs that the arms go through being effected in a negative way. Which is why a modification to the rear toe arm mount on the knuckle is likely necessary to achieve proper suspension geometry out back (like the picture I posted of the S15 with Z32 uprights).

Danny, I do not believe there is enough material on the front spindle to just cut the bottom off and bolt something else on. You can see the GP Sports knuckles have a good 1/2 inch more material then the stock knuckles where the bottom part bolts on.

It IS a shame that GP Sports stopped making them....but at the same time it was an unmarketable product. Very few S-chassis owners can afford/are willing to throw a good 1000-1200 bucks for a set of knuckles here in the US. Especially when it can be corrected by just raising the car up (which is what people who care about performance usually do).

NiSilS14

12-28-2009, 07:52 PM

Can we sticky this? This is very good.

PoorMans180SX

12-28-2009, 09:40 PM

He's talking about the actual arcs that the arms go through being effected in a negative way. .

Using a longer shank doesn't affect the arc of the control arm at all. It merely moves it down in it's arc. It moves exactly the same way, think about it. The other control arms stay the same as well.

EDIT: The relationship between the arms does change slightly, but as stated below, the change is not really a performance-hurting one.

mmdb

12-28-2009, 10:56 PM

Using a longer shank doesn't affect the arc of the control arm at all. It merely moves it down in it's arc. It moves exactly the same way, think about it. The other control arms stay the same as well. Their relationship does not change. Just because the lower control arm is spaced down doesn't mean that the arms move any different than they used to.

wrong. For the front, being a macphearson strut design, has a 1:1 ratio in relation for the lca moving 1" and the shock compressing 1", so you could almost assume it does not affect other suspension components. The problem is more apparent in a multilink suspension such as the rear links on our car. It's difficult to conceptually visualize, but a few hardcore racing companies have developed new spindles in contrast to addig spacers under the lca to combat the negative affects of lowering a production based vehicle while preserving the initial suspension dynamics from the factory. In other words there more to adding spacers between the knuckle and lca.

Def

12-28-2009, 11:51 PM

wrong. For the front, being a macphearson strut design, has a 1:1 ratio in relation for the lca moving 1" and the shock compressing 1", so you could almost assume it does not affect other suspension components. The problem is more apparent in a multilink suspension such as the rear links on our car. It's difficult to conceptually visualize, but a few hardcore racing companies have developed new spindles in contrast to addig spacers under the lca to combat the negative affects of lowering a production based vehicle while preserving the initial suspension dynamics from the factory. In other words there more to adding spacers between the knuckle and lca.

Not really sure what you're getting at, but all you would change(besides the roll center) would be the camber and possibly toe curves(I'm imagining this might stay the same). If anything, you'll probably increase your camber gain in the rear, even though that's not really a problem when lowered.

As for the GP Sports knuckles - if you're fine with two bolts in bending, why not just drill out the stock spindle and use a 3/4" bolt in bending in place of the balljoint?

mmdb

12-29-2009, 12:06 AM

Just making the point that it requires more attention to correctly raise the roll center given a multi-link suspension. Unless I misread.

PoorMans180SX

12-29-2009, 12:26 AM

Just making the point that it requires more attention to correctly raise the roll center given a multi-link suspension. Unless I misread.

Do you realize I started this thread? Hahaha, I know more than you think, though I think Def knows more than all of us.

It's difficult to conceptually visualize, but a few hardcore racing companies have developed new spindles in contrast to addig spacers under the lca to combat the negative affects of lowering a production based vehicle while preserving the initial suspension dynamics from the factory. In other words there more to adding spacers between the knuckle and lca.

Did you read through the first post? There are a couple that I posted up.

Anyway, I was responding to racepar1's post.

You have a point, but as I stated in my post, the only real difference is LCA length. Which is really quite slight, as the angle of the ball joints makes the additional length of the ball joint/shank not the length the control arm is extended. Here's my crude Paint example:

http://i24.photobucket.com/albums/c25/Turbo711/LCA2.jpg

And as Def stated, the camber and toe curves change very little with this.

I think you guys are making it out to be a bigger deal than it actually is.

RastaS13

12-29-2009, 01:07 AM

Geder done andy!!!!!

ballinnmiami240sx

12-29-2009, 06:28 AM

This is the reason we went ahead with making our set up. Alot of assumptions, I think's, and what if's. Until we get this 95katurbo's car on an alingment rack and take it to the track we will not know the results. Kinda ol'skool engineering I call it. Build it and take it to the track and beat the piss out of it. If it works everyone will want to have his set up. If it breaks into a billion pieces then we will get "the i told you so". As I look at the set up on the ground with the new GM ball joint set up we will be spacing the LCA about 20mm down. The spherical bearing that I intalled works with the up and down movement of the LCA. Essentially affecting nothing at this point. Under lateral G's we will have to wait and see. As far as I can tell I see nothing but positives from our set up. It beats the crap out of an old worn out rubber set up.

scottie

12-29-2009, 08:07 AM

Where did you find the pic of Powered Max fabbing some new hubs?

PoorMans180SX

12-29-2009, 09:26 AM

Where did you find the pic of Powered By Max fabbing some new hubs?

BTW, it's Parts Shop MAX. Powered By MAX is the website name.

POWERED BY MAX: ForumsÃ£â‚¬â‚¬Ã£Æ’â€¢Ã£â€šÂ©Ã£Æ’Â¼Ã£Æ’Â©Ã£Æ’ / Ã¤Â½Å“Ã£ÂÂ£Ã£ÂÂ¦Ã£â€šâ€šÃ£â€šâ€°Ã£Ââ€žÃ£ÂÅ¸Ã£Â â€žÃ£Æ’â€˜Ã£Æ’Â¼Ã£Æ’â€ž Wish List / Rear knuckle (http://www.gtfactory.jp/cms/e107_plugins/forum/forum_viewtopic.php?5048)

lazysk8er2

12-29-2009, 09:40 AM

good info subscribed

mmdb

12-29-2009, 11:18 AM

Found these on Driftworks' website here. (http://www.driftworks.com/forum/driftworks-shop/81334-driftworks-hubs-7.html)

http://media.driftworks.com/assorted/NewUprights1.jpg

http://media.driftworks.com/assorted/NewUprights2.jpg

PoorMans180SX

12-29-2009, 12:07 PM

Solid! I've just found out they also make tie rod offset spacers (found them in that link). These space the tie rods farther forward to correct for "over centering" of the steering rack with all that increased angle. Sick!

Check them out:

http://i24.photobucket.com/albums/c25/Turbo711/RackSpacer.jpg

http://i24.photobucket.com/albums/c25/Turbo711/RackSpacers3.jpg

http://i24.photobucket.com/albums/c25/Turbo711/RackSpacers7.jpg

Original post edited!

GSXRJJordan

12-29-2009, 01:20 PM

^^^ Driftwerks = killer stuff. I'm happy to see innovation still being done in the S-chassis community!

I might have to get some measurements and CNC a spindle... I wonder how long it would take and how many pieces I'd screw up before I got it right lol...

93nismo

12-29-2009, 02:02 PM

i love learning things about my car. this is the most ive learned in probably the 3 weeks ive been on break. awsome.

nathanong87

12-29-2009, 02:25 PM

!Zar!

12-29-2009, 03:30 PM

I'd like to try out those offset tierod spacers. Are they up for sale yet?

PoorMans180SX

12-29-2009, 05:22 PM

I'd like to try out those offset tierod spacers. Are they up for sale yet?

Negative. Not on their website at least.

It would be kinda nice if some people in the US made some of this stuff. Not that I don't want to support Drift Works, but I can't imagine it being very affordable to ship stuff from England.

Oh well.

ManoNegra

12-29-2009, 05:41 PM

Negative. Not on their website at least.

It would be kinda nice if some people in the US made some of this stuff. Not that I don't want to support Drift Works, but I can't imagine it being very affordable to ship stuff from England.

Oh well.

I'm oblivious, are those only for drifter knuckles with stupid crazy steering angle?
looks kinda sketchy to me.

PoorMans180SX

12-29-2009, 05:54 PM

I'm oblivious, are those only for drifter knuckles with stupid crazy steering angle?
looks kinda sketchy to me.

Yeah, they keep the tie rods from moving ahead of the knuckle at extreme steering angles.

That's a Chromoly bolt, CNC'd billet aluminum, and a tie rod. How is that sketchy?

nieko

12-30-2009, 03:41 AM

wow... driftwerks if amazing... so genius.

when i end up getting knucles and fun, im buying those.

ballinnmiami240sx

12-30-2009, 07:18 AM

those have been around for about 2 years now. The first time I saw them was on the C's garage yellow coupe.

ManoNegra

12-30-2009, 07:46 AM

Yeah, they keep the tie rods from moving ahead of the knuckle at extreme steering angles.

That's a Chromoly bolt, CNC'd billet aluminum, and a tie rod. How is that sketchy?

just wondering how a car would drive under normal conditions, daily for example, with those
or are they a drift only, trailered back and forth to track car deal?

ballinnmiami240sx

12-30-2009, 08:35 AM

I dont see how it could effect anything. All you are doing is correcting geometry when the car is lowered or has extreme angle. I daily drove my car with modded knuckles and super low ride height. Did it suck? Yes, but I knew that was going to happen. Now did it perform on track. Hells yeah!!!! I dont drive my track car on the street anymore. The coilovers will rattle your teeth lose and the road noise is loud. hahaha.....I just realized I sounded OLD.

mmdb

12-30-2009, 09:44 AM

I read a post on driftworks concerning those offset spacers. They were originally developed and used in japan, but during usage they either broke or caused heavy wear on the steering rack causing it to deform. I'll try to find the post.

PoorMans180SX

12-30-2009, 10:43 AM

They were talking about the URAS ones, which are a different design and less quality.

Driftworks designed theirs to be better.

I'll quote:

Now that is a good call

If we were to do it, they wouldn't be the same design as the URAS ones. We're hearing reports from Japan of those ones either coming loose or snapping, but we have something else up our sleeves

Jonnie Fraz

12-30-2009, 10:56 AM

Def

12-30-2009, 01:19 PM

They were talking about the URAS ones, which are a different design and less quality.

Driftworks designed theirs to be better.

I'll quote:

It doesn't matter how much "better" they design the materials, that part still puts the steering rack into bending when it wasn't designed to handle that(inner tie rods pivot, and it doesn't locate the front spindle at all, so no bending). The rack might handle it for a bit, but I imagine the seals aren't up for that kind of beating.

white92_s13

12-30-2009, 06:56 PM

i have a few question just pertaining to basic angles and mods.

So I have a corolla and i have played with angle a little bit.

My first setup was some steering rack spacers, stock inners and megan outer. ran great got good angle. and to correct the roll center i used battle version NRCA.

so now i have a fresh chassis to play with.

I want to get MORE angle by modifying some stock knuckles.

MY idea.....?
take a stock knuckle off. take a pre measured chunck out. not much. and then heat it with a torch and weld it back together. shortening the knuckle with increase the leverage and gain more angle?

so with shortened knuckle length, megan tie rod ends, battle version roll center adjusters, t3 camber plates, and some battle version steering rack spacers, a fresh alignment i should have a good angle setup? in theory should be more then i had before with not having shorten'd knuckles.

i dont have to worry about the tie rod hitting the lower control, and i already have my roll center adjusted with the battle version nrca.

PoorMans180SX

12-30-2009, 08:10 PM

It doesn't matter how much "better" they design the materials, that part still puts the steering rack into bending when it wasn't designed to handle that(inner tie rods pivot, and it doesn't locate the front spindle at all, so no bending). The rack might handle it for a bit, but I imagine the seals aren't up for that kind of beating.

Good to know. I guess the only way to correctly do this is to actually move the rack forward. Fabrication time.

mmdb

12-30-2009, 09:02 PM

PoorMans180SX

12-30-2009, 09:50 PM

Another FYI (sorry i know). I'm using the GP Sports Hyper knuckle right now, and because it spaces the lower control arm and the spindle it added a bit of negative camber. It's likely that during compression the front suspension cambers inward, and by fixing the roll center it's added much negative camber. This could take a toll if your camber plates are out of adjustment which doesn't allow you to run less negative camber. Currently I'm stuck running 1.8' negative camber and out of adjustment.

Found this in a Sport Compact Car article:

On MacPherson strut-equipped cars, the wheel will gain negative camber under roll as long as the lower control arm is positioned less than 90 degrees relative to the strut axis. Unfortunately, many enthusiasts with MacPherson strut-equipped cars lower their cars too much and make this angle greater than 90 degrees. Beyond 90 degrees, the suspension will gain positive camber instead of negative as it compresses, significantly compromising grip

http://i24.photobucket.com/albums/c25/Turbo711/0512_sccp_10_z_suspensiondiagram.jpg

I don't know why it would be a problem, as gaining negative camber in a corner is good. Do you mean if you have already adjusted your camber plates to run a lot of negative camber, then correct your roll center, your car will run too much camber in corners?

Jonnie Fraz

12-30-2009, 10:17 PM

Found this in a Sport Compact Car article:

I don't know why it would be a problem, as gaining negative camber in a corner is good. Do you mean if you have already adjusted your camber plates to run a lot of negative camber, then correct your roll center, your car will run too much camber in corners?

This is a great graphic! I remember reading this series in SCC back before the mag went to shit.
This also explains why I have seen some of these super low cars running retarded front camber. That would also get the angle below 90.
I like changing the pick-up points better, but to each is own. Please keep filling this thread with great info.
One thing that I keep thinking about is with suspention set-ups as stiff as have been discussed earlier what kind of compession travel are we talking about?

mmdb

12-30-2009, 10:46 PM

I can't hit more than 2.3' of negative camber. This is probably due to my shock manufacterer being partially misinformed, but it could be a potential problem for others as well. Another problem that could arise is the shock length. When the knuckle is raised the shock is also compressed. Shocks with a separate perch and preload adjustment will be ok.

s13silvia123

12-30-2009, 10:56 PM

i should of started this thread years ago when i was curious about this and wanted to learn more back then.

VIPDRFT

12-31-2009, 12:11 AM

I stumbled upon this. They make knuckles that look like the Driftworks ones. Flame away.

http://www.cens.com/cens/publication/9/512/56551_l.jpg

PoorMans180SX

12-31-2009, 12:29 AM

MY idea.....?
take a stock knuckle off. take a pre measured chunck out. not much. and then heat it with a torch and weld it back together. shortening the knuckle with increase the leverage and gain more angle?

Yeah, that should work, just be careful welding on cast iron, it's hard to get good penetration! Also, make sure the tie rod holes stay in the same position in relation to the knuckle, just moved in closer. This will keep your steer feel the same.

This is a great graphic! I remember reading this series in SCC back before the mag went to shit.
This also explains why I have seen some of these super low cars running retarded front camber. That would also get the angle below 90.
I like changing the pick-up points better, but to each is own. Please keep filling this thread with great info.
One thing that I keep thinking about is with suspention set-ups as stiff as have been discussed earlier what kind of compession travel are we talking about?

Hmmm...I would say about 4 inches, give or take a few? Most coilovers run 8/6, and cars roll very little with these and even stock anti-roll bars. Heck, most coilovers don't have more than 4-6inches of shock travel anyway.

I know with my 10/8 there was pretty much zero roll, and with my 12/10 there was absolutely no roll. But then again, this was with less-than-grippy tires.

Maybe the grip guys running slicks can comment on body roll a little more.

But anyway, part of the reason you run a stiff suspension is to reduce camber and toe change with body roll. So with a corrected roll center, this should allow you to run just a little less static camber. I guess it depends on how your strut is angled and how low your car is. Those guys running extended front lower brackets on their coilovers are actually at a disadvantage there; they make the angle greater.

I stumbled upon this. They make knuckles that look like the Driftworks ones. Flame away.

Taiwan? Making a knock-off?!?! What?!?!? Hahahaha.

mmdb

12-31-2009, 12:44 AM

I stumbled upon this. They make knuckles that look like the Driftworks ones. Flame away.

The Taiwanese company could have copied a Japanese manufacturer initially; I know I've seen this before. Though, the design would be somewhat similar between manufacturers, the geometry might have changed. Anyway, I would rather have a part made in England rather than in Taiwan... but I guess it could go both ways (a part failing that is).

GripTerror

12-31-2009, 04:58 AM

Driftworks GeoMaster Hub Knuckles - Drifting forum - Driftworks (http://www.driftworks.com/forum/driftworks-shop/102238-driftworks-geomaster-hub-knuckles.html#post1281774)

SoSideways

12-31-2009, 09:00 AM

Dang, 695 pounds for all 4... that's about the price of just the GP Sports front knuckles.

Good deal, but who imports their stuff?

GripTerror

12-31-2009, 09:03 AM

Yeah I would hope someone imports this stuff as its gona be arm and a leg on customs/taxes rape as well as shipping. This is the most awesome part ever imo

scottie

12-31-2009, 10:39 AM

They (DriftWorks) cant estimate shipping? I wonder who rhdjapan uses for shipping because their stuff wasnt that bad on shipping charges to be honest. I wouldnt be surprised if they can ship international through USPS for a fair price. I may need to email them about shipping international.

GripTerror

12-31-2009, 12:01 PM

yeah but they charge arm and a leg on the product itself. I've bought from rdhjapan before... insane prices on stupid simple stuff just because its jdm... seriously... but they are friendly.

95KA-Turbo

12-31-2009, 12:13 PM

I have a friend stationed in the UK, I don't see why he couldn't get the spindles shipped to him, then ship them out through the base USPS and get very reasonable rates on shipping.

SoSideways

12-31-2009, 12:26 PM

I have a friend stationed in the UK, I don't see why he couldn't get the spindles shipped to him, then ship them out through the base USPS and get very reasonable rates on shipping.

Yeah but not everyone has a hook up in the UK for the purpose of shipping something.

I think what we were trying to get at is to have a more permanent solution to the shipping dilemma for Drift Works stuffs.

95KA-Turbo

12-31-2009, 01:07 PM

Right, I should have worded it a little differently. If anyone is serious about wanting them I can talk to my friend.

roboticnissan

12-31-2009, 01:11 PM

So the basic idea is to try to get all arms parralel with the ground while under load and keeping all arms as even as possible at the same time??

95KA-Turbo

12-31-2009, 01:22 PM

Right, a more correct way of saying it might be - preserve the stock suspension geometry as much as possible.

I believe there are improvements that can be made to the stock geometry, but that is much more complicated then just correcting it back to stock. I figure if you make everything adjustable, you can tweak it at the track and get it set up for your own personal preference.

d0pe240

12-31-2009, 06:12 PM

i was wondering would these greddy and moonface ball joints/roll center adjusters be enough to make the control arm straight enough for a slammed 240sx?

http://www.rhdjapan.com/media/catalog/product/cache/1/image/5e06319eda06f020e43594a9c230972d/57025/Image/Normal/Image2.jpg

http://www.rhdjapan.com/media/catalog/product/cache/1/image/5e06319eda06f020e43594a9c230972d/56343/Image/Normal/Image1.jpg

95KA-Turbo

12-31-2009, 06:20 PM

No, at most those give 1/3-1/2 inch of adjustment.

The only ones that actually do anything are the top of the line Moonface ones....IMO 1/2 inch of adjustment isn't worth 450 bucks.

d0pe240

12-31-2009, 06:33 PM

No, at most those give 1/3-1/2 inch of adjustment.

The only ones that actually do anything are the top of the line Moonface ones....IMO 1/2 inch of adjustment isn't worth 450 bucks.

yeh they didnt look long enough, like how your setup is. how much do you think your set up cost, just for the roll center adjusters?

PoorMans180SX

12-31-2009, 06:41 PM

Remember, if they space the ball joint UP, then they don't actually do anything. The pivot point has to remain the same, the shank is what is supposed to be taller.

95KA-Turbo

12-31-2009, 06:44 PM

yeh they didnt look long enough, like how your setup is. how much do you think your set up cost, just for the roll center adjusters?

Since you have to ream the spindle to accept the shank I am using and weld parts to the LCA, it will have be a LCA + spindle package. I will talk to Danny and let you know. It should be pretty affordable compared to whats out there.

articdragon192

12-31-2009, 08:07 PM

Pardon my ignorance, but what does overcentering mean? And why is it bad?

GSXRJJordan

12-31-2009, 08:25 PM

Pardon my ignorance, but what does overcentering mean? And why is it bad?

That's when you pass the point at which more side-to-side movement moves the knuckle out, and the knuckle comes back in - then you go to turn the other way and the tie rod is stuck. Hard to explain, hopefully that gives you a visual.

udon!

12-31-2009, 08:33 PM

so for a basic (begginer) roll correction setup on a slammed 240sx you would want inner/outer tie rods, tension rods, and the ruca and rear toe rod?

sorry im a little new to the suspension stuff...

articdragon192

12-31-2009, 08:34 PM

Ahhh, I got it now. Ok makes sense.

95KA-Turbo

12-31-2009, 08:47 PM

That will give you an alignment.

Tie rods adjust toe, but if you space them down to be flat you'll correct bump steer.
Tension rods adjust caster
RUCAs adjust rear camber
Toe rods....adjust toe out back, haha.

The only way to adjust the roll center is to modify the ball joints on the LCAs.

udon!

12-31-2009, 09:27 PM

95KA-Turbo

12-31-2009, 09:35 PM

The BEST thing to do would be to buy a modified spindle to correct the roll center some, while making the geometry of the other arms proper as well AND buying an adjustable LCA so you can control everything.

I am pretty sure the ikeya arms don't adjust enough for a completely slammed car without some other form of adjustment as well.

tt99ol

12-31-2009, 09:57 PM

I've been looking into adding squat and adjusting my roll center lately
the driftworks spindles adjust 50mm rear and 45mm front
if you raise the subframe in the rear as well you get nearly 3" total of correction
Phil from driftworks said the rear grip is incredible with the spindles and added squat
His car drives great too so its proof
I'm gonna get their spindles maybe early 2010 so maybe i will get together with a couple of you and we can make a jig up and use heim joints instead of poly bushings

An idea I've had for a while now was to space the front crossmember down an inch to get the engine lower in the chassis and then raise the flca an inch to compensate
My question is, what kind of effect would that have on the tie rods as they will be an inch lower on their inner pivot? I think it would increase bump steer which makes the whole thing pointless.

95KA-Turbo

12-31-2009, 10:12 PM

It would make the bump steer and roll center worse, as well as put added forces on the tension rods for no reason.

If you want the engine lower make custom motor mounts/oil pan.

udon!

12-31-2009, 11:04 PM

PoorMans180SX

12-31-2009, 11:51 PM

fuck this is compricated.

what about this:

Ikeya Formula - Roll Center Adjuster Pillow Lower Arms Kit - Nengun Performance (http://www.nengun.com/ikeya-formula/roll-center-adjuster-pillow-lower-arms-kit)

Those are just adjustable lower control arms. Those will give you probably 15mm of roll center correction. On a slammed car, a new RCA knuckle is needed. This is why there's so much excitement over the Driftworks and PSM knuckles.

udon!

12-31-2009, 11:58 PM

Those are just adjustable lower control arms. Those will give you probably 15mm of roll center correction. On a slammed car, a new RCA knuckle is needed. This is why there's so much excitement over the Driftworks and PSM knuckles.

wait are you talking about the pbm super angle kit?

PoorMans180SX

01-01-2010, 01:41 AM

wait are you talking about the pbm super angle kit?

My bad, I should have specified. The PSM REAR drop knuckles/spindles that they are making.

Happy New Year!

kognition

01-01-2010, 02:39 AM

This is from an associates time attack car. I will let you guess who's it is.
Hint: It's an S15 with a couple championships under it's belt. :2f2f:
The upright's are Z33's. And there you go.
http://kognitiondesign.com/rlca-1.jpg
http://kognitiondesign.com/rlca-2.jpg

PoorMans180SX

01-01-2010, 02:45 AM

Have any shots of the whole rear setup?

Since all the arms are JIC, I'm going to guess the JIC/Hankook S15?

If that's true, I'm stoked to find out more details if you have them. That car is amazing! Probably my biggest single piece of inspiration.

Hashiriya415

01-01-2010, 03:46 AM

I figured it out how to make to solve the problem very cheap.
Find the Delorean time machine, go back to the past and tell Nissan to make the 240's 3" lower, and then there should be no issue, unless some of you want to lower it more.

95KA-Turbo

01-01-2010, 07:32 AM

Those can't be Z33 rear uprights. They don't even remotely look like that and don't remotely have the same suspension set up as a S chassis car.

Z33:

http://www.meganracing.com/uploadImage/regular/DSC04985x8.jpg

http://img.mudah.my/images/75/7503669951.jpg

vs

S15:

http://www.dragsport.com/issue/2008/images/1108/s15-3.jpg

You can see the same hump in the above picture that the modified spindle has on it. They just cut/welded on the stock S-chassis spindles.

This is what I want to do:

http://www.dragsport.com/issue/2007/images/0707/s15-5.jpg

Which is another S15 time attack car, they are just using Z32 uprights.

GripTerror

01-01-2010, 07:33 AM

PoorMans180SX

01-01-2010, 08:13 AM

you know this thread makes me happy.. not just that we're finally getting more readily available solutions to fix our screwed up geometry but... the fact that zilvia is asking about suspension geometry and not slamming their car LOL :D

My only concern is getting rid of polyurethane or getting them to make spherical bearings version. As well as having the option for a z32 spindle for those of us that run z32 fork style shocks in the back.

Well...The whole point for me is that you can slam the car and still have good geometry (like a real race car) :ddog:

That's why I'm pumped for the PSM rear knuckles, which will have heim joints.

And you can always convert back to regular lower brackets.

95KA you're right, those are the S15 knuckles.

GripTerror

01-01-2010, 08:34 AM

The reason i want them is for the corrected geometry while lowering center of gravity not for appearance but for performance :)

Im looking forward to see what PSM has in store... i want spherical bearings... and a z32 rear option.

I wonder if this would work with a skyline front (double wishbone setup).. if i ever decided to cut up my front and put an r32 front or something silly like that.

Oh and the pix posted were from the s15 i believe are the jic s15...

SoSideways

01-01-2010, 11:15 AM

So.... about those Driftworks knuckles... :)

About how much would it be after all the hassle of buying them from Driftworks, then having them shipped here, and giving your buddy some beer moneys, 95ka-turbo?

GripTerror

01-01-2010, 11:28 AM

You know we can wait for driftworks' response to all our concerns.

Then again PBM/PSM will have it stateside no doubt AND with spherical bearings (screw polyurethane... i dont want any bushings/binding/whatever in my track car).

kognition

01-01-2010, 12:17 PM

My error. S15= iron Z32/Z33= Aluminum
I def like the Aluminum better. As thick as it is, it would seem that the energy transfer on the alluminum would be better.

Those can't be Z33 rear uprights. They don't even remotely look like that and don't remotely have the same suspension set up as a S chassis car.

Z33:

http://www.meganracing.com/uploadImage/regular/DSC04985x8.jpg

http://img.mudah.my/images/75/7503669951.jpg

vs

S15:

http://www.dragsport.com/issue/2008/images/1108/s15-3.jpg

You can see the same hump in the above picture that the modified spindle has on it. They just cut/welded on the stock S-chassis spindles.

This is what I want to do:

http://www.dragsport.com/issue/2007/images/0707/s15-5.jpg

Which is another S15 time attack car, they are just using Z32 uprights.

kognition

01-01-2010, 12:40 PM

The car is no longer here in the states, i think it is in Australia or back in Japan.
http://kognitiondesign.com/rear-left.jpg
http://kognitiondesign.com/rear-right.jpg
http://kognitiondesign.com/rear.jpg

Have any shots of the whole rear setup?

Since all the arms are JIC, I'm going to guess the JIC/Hankook S15?

If that's true, I'm stoked to find out more details if you have them. That car is amazing! Probably my biggest single piece of inspiration.

PoorMans180SX

01-01-2010, 02:31 PM

The car is no longer here in the states, i think it is in Australia or back in Japan.
http://kognitiondesign.com/rear-left.jpg

What's this?! Do I spot relocated inner pivot points on those FLCAs?

You grip guys should be taking notes. That's the fastest grip S-chassis that ever came to the states.

http://i24.photobucket.com/albums/c25/Turbo711/JICS15.jpg

Mini-stretched tires, slammed ride height, and stock anti-roll bars.

You know we can wait for driftworks' response to all our concerns.

Then again PBM/PSM will have it stateside no doubt AND with spherical bearings (screw polyurethane... i dont want any bushings/binding/whatever in my track car).

Yeah, now we'll just have to wait for Driftworks to sell them in pairs (so we can get the fronts). Or for PSM to announce they're going to make front ones.

udon!

01-01-2010, 02:31 PM

My bad, I should have specified. The PSM REAR drop knuckles/spindles that they are making.

Happy New Year!

oh ok, so do you use the super angle kit and the rear knuckles?

what do you use for the front

SoSideways

01-01-2010, 02:35 PM

The fronts aren't roll center corrected.

They are mainly made for more angle without using aftermarket tie rod ends like the SPL Parts tie rod ends.

PoorMans180SX

01-01-2010, 02:48 PM

oh ok, so do you use the super angle kit and the rear knuckles?

what do you use for the front

The fronts aren't roll center corrected.

They are mainly made for more angle without using aftermarket tie rod ends like the SPL Parts tie rod ends.

Yeah Udon, PSM's front knuckles are not roll center adjusting. They just adjust for bump steer (tie rods).

That's why everyone is in for the Driftworks. Look on the first post. See how the hubs are moved up in the front knuckles (towards the shock mounting bolt holes)?

roboticnissan

01-01-2010, 03:16 PM

Yeah Udon, PSM's front knuckles are not roll center adjusting. They just adjust for bump steer (tie rods).

That's why everyone is in for the Driftworks. Look on the first post. See how the hubs are moved up in the front knuckles (towards the shock mounting bolt holes)?

so you would put the driftworks knuckles above the psm ones becuz they adjust for roll center?? and with the psm front knuckles you will get increased bump steer with out other suspension like tie rods???

PoorMans180SX

01-01-2010, 03:24 PM

so you would put the driftworks knuckles above the psm ones becuz they adjust for roll center?? and with the psm front knuckles you will get increased bump steer with out other suspension like tie rods???

Yes, Driftworks adjust for roll center and give you big angle.

No, PSM's correct bumpsteer by spacing the tie rod ends farther down (level with the control arm).

Carbomb

01-01-2010, 03:36 PM

http://dangdrifters.com/images/aPRIL%2028%20026.jpg
http://dangdrifters.com/images/slappy%20001.jpg
http://dangdrifters.com/images/dang%20sub.jpg
Modified knuckles / spindles are bump steer and shortened for angle. lca's are boxed / dimpled / and modifed for clearance for tie rod end, subframe is modified for adjusting geo for less bind and adding a tad more angle to the mix with a inner tie rod like a peak pro Peak Performance - PROSUSITRS13 Nissan S13/S14 Inner Tie Rod - PRO (http://www.peak-performance.net/content/view/163/81/) which has a few mm machined on tie rod with a add on spacers your pretty much good for angle and getting a roll center adjuster in lca with this combo
then you just need to get clearance for wheels the inner lip on rear of front wheel well needs to be cut and welded flush, and if your low low , you might wanna "tub" your fenders I just hit the place it was rubbing with a hammer like alot of others do... less work and more time to drive...

Using a ikeya style lower control arm also will gain more angle if you cut the bump stop off. this is the most extreme shit you can do... you really can back it in while sliding.

awesome thrad.
http://dangdrifters.com/images/danggg.jpg
http://dangdrifters.com/images/vosko.jpg

Teknolust72

01-01-2010, 03:59 PM

My friend was the race mechanic for the JIC S15 last year, and he mentioned they also raised their entire steering rack by drilling out new position holes for the steering rack brackets.

Jonnie Fraz

01-01-2010, 05:53 PM

Now I just got through reading the 2010 rules for Formula D. I am not pretending that I understand all aspects of the rules, but the ones pertaining to the front and rear sub frame seem pretty clear.
8.3.4 Front cross member and/or front or rear sub-frame
Front and rear sub-frames and cross members must be stock and
available on the exact model that is competing in Formula Drift. The
subframe must also be mounted in the exact stock location, without
being moved in any plane.
Front subframes may only be modified to directly allow for oilpan /
starter clearance and steering rack relocation. The front subframe must
retain intact on at least one major member on one face that spans the
entire width of the subframe, thereby keeping the original dimensions of
the subframe intact. Any other modifications, cutting, welding,
strengthening, etc is not allowed.
Rear subframes may only be modified to allow for mounting or
relocating a differential. The rear subframe must retain at least one
major member that spans the entire width of the subframe, thereby
keeping the original dimensions of the subframe intact. Any other
modifications, cutting, welding, strengthening, etc is not allowed.

To me that means no swapping S14-S15 subframes into a S13 chassis. No relocating any pick up points on the chassis.
Now if you are not worried about that sanctioning body then no prob.

95KA-Turbo

01-01-2010, 06:09 PM

That's why I made lower control arms, to comply with the rules.

Ghostdrifter

01-01-2010, 06:50 PM

Kognition in which way did the JIC team modify the rear toe mount? Did they rotate it so the pick up point is lower?

95KA-Turbo

01-01-2010, 07:09 PM

They made it so the toe arm is parallel to the LCA, how it is from the factory.

PoorMans180SX

01-01-2010, 08:42 PM

http://dangdrifters.com/images/dang%20sub.jpg

That's a good idea. Moving the steering rack forward by moving that whole chunk of subframe forward.

My friend was the race mechanic for the JIC S15 last year, and he mentioned they also raised their entire steering rack by drilling out new position holes for the steering rack brackets.

Ahhhh, so they moved the FLCA inner pivots up and the steering rack. Keeping the arcs the same.

Formula D Rules, etc, etc.

Well, looks like I won't ever be competing in Forumula D. Oh well, I never did like FD.

I can see the modification thing, but no strengthening? I think that's kinda stupid.

Made some changes to the OG post.

Jonnie Fraz

01-01-2010, 09:39 PM

Well, looks like I won't ever be competing in Forumula D. Oh well, I never did like FD.

I can see the modification thing, but no strengthening? I think that's kinda stupid.

Made some changes to the OG post.

I hear ya! I am really not following the re-enforcing the subframe rule.
Tons of people out there running modded subframes, as well as the S14 subframe in the S13 chassis or s15 subframe in the S14.
Now the rules do state that you can get an exception from Formula D, but the pick up points can not be moved more than an inch.

I also remember a quote from one of the crew cheifs I ran across saying..." It's our job to cheat and it is their job to catch us."

PoorMans180SX

01-01-2010, 09:43 PM

I hear ya! I am really not following the re-enforcing the subframe rule.
Tons of people out there running modded subframes, as well as the S14 subframe in the S13 chassis or s15 subframe in the S14.
Now the rules do state that you can get an exception from Formula D, but the pick up points can not be moved more than an inch.

Hahaha, so how does that make sense? The pickup points can't be modified, but then they can?

Pretty dumb.

Clearly the front pickups were modified on the JIC S15. They must have got an exception.

kognition

01-01-2010, 10:30 PM

Remember that the S15 left the states sometime late last year. Maybe Oct or Dec. I don't follow the Drifting rules in FD, as i am not a drifter. But maybe they did not have rules restricting it at the time? How much did the car drift? I only know it from time attack. But in any case, it's gone now. And i think that they only have the S14 now. Which has been at the fabricators forever.

Hahaha, so how does that make sense? The pickup points can't be modified, but then they can?

Pretty dumb.

Clearly the front pickups were modified on the JIC S15. They must have got an exception.

udon!

01-01-2010, 10:41 PM

Yeah Udon, PSM's front knuckles are not roll center adjusting. They just adjust for bump steer (tie rods).

That's why everyone is in for the Driftworks. Look on the first post. See how the hubs are moved up in the front knuckles (towards the shock mounting bolt holes)?

GOT IT! so basically if youre car is fucking slammed with driftworks or psm knucklesyou may not have perfect roll center, but its going to be ALOT better than stock knuckles because on the driftworks/psm knuckles the part that hooks up to the links is much lower than stock.

is that right?

udon!

01-01-2010, 10:48 PM

how does a tension rod work?
how does a traction rod work?

can you guys show me pics of these installed?

PoorMans180SX

01-01-2010, 11:19 PM

GOT IT! so basically if youre car is fucking slammed with driftworks or psm knucklesyou may not have perfect roll center, but its going to be ALOT better than stock knuckles because on the driftworks/psm knuckles the part that hooks up to the links is much lower than stock.

is that right?

Exactly

how does a tension rod work?
how does a traction rod work?

can you guys show me pics of these installed?

Pretty newbish stuff man, although the traction rod is a little harder to understand.

Found this stuff on PDM Racing

PDM Racing - Battle Version Suspension Parts (http://www.pdm-racing.com/products/battleversion.html)

Tension Rods:
Adjustable TC Rods are crucial to increase positive caster on Nissans. Caster is a very good alignment quality to induce into your Nissan, as this allows you to reduce your static camber more, yet when the car turns in, negative camber will increase which generates higher cornering ability. Translation: less inner tire wear when the car is driving in a straight line which is over 85% of the time, yet when it comes time to corner, your car will have enough caster to create good negative camber to make your car feel like itâ€™s cornering on rails. Also, having adjustable caster means you can equalize caster from left to right on your Nissan to maximize turning performance both left and right. (On our Hunter computerized alignment rack, we notice itâ€™s common to see 240SXâ€™s with left to right caster specs out by as much as 1.5 degrees. Some are from curbing accidents, others are off-balance straight from Nissan Japan!) By adding adjustable TC Rods, you ensure your car will corner equally fast turning left, or turning right.

The TC Rod is the ONLY arm that locates the bottom control arm on the 240SX. When a car is under severe braking from 100 mph, the force on that TC Rod is the most extreme force that any single suspension component will experience. So replacing the stock TC Rod bushings with a spherical bearing, will ensure under braking your front end will not shimmy or wander as caster and toe will change from the TC Rod bushing flexing back and forth. For example, many of our 300ZX customers complain of brake shimmy and thinking the rotor is the culprit, they have their rotors turned. Most often, the culprit is a worn OEM TC Rod bushing which is a viscous filled rubber membrane, which is good for comfort and compliance, but makes for a terrible locator for an arm that sees such severe duty. Over time, the stock outer membrane wears from repeated force, heat and oils. Quite often we see cars come into our shop with completely blown-open TC Rod bushings.

Traction Arms:
The forward traction link arms locate the rear spindle assembly, and controls the forward and aft movement of the rear upper suspension assembly on independent rear suspension (IRS) cars as the suspension moves through itsâ€™ engineered movement. While the stock stamped steel arms works fine for most applications, itâ€™s when you drastically lower the car for race or drift, that there needs to be arm adjustment for setting the rear bump steer.

Bump steer, in short, is the change in toe settings a suspension has as it moves through itâ€™s compression and rebound cycles. Nissan Engineers designed toe in under compression which is safer than toe out, but for optimum settings, racers like to have control of bump steer to dial in the amount of toe change their race cars will encounter as it goes over bumps and dips on the course. Cars that are â€œnervousâ€ or â€œtwitchyâ€ are often ones that have bad bump steer, so the car literally steers itself as the car goes into a bump. While not as critical as the rear toe links or upper rear control arms, Battle Version Rear Forward Traction Link Arms will complete your rear suspension by positively locating the rear spindle for very minimal rear suspension for and aft flex. For those that know how to plot your rear bump steer, this allows these racers to properly set up the rear suspension to their personal tastes.

udon!

01-01-2010, 11:40 PM

yaya. thats pretty much the last n00b shiz i didnt really know about. kinda was embarrassed to ask...

PoorMans180SX

01-01-2010, 11:44 PM

yaya. thats pretty much the last n00b shiz i didnt really know about. kinda was embarrassed to ask...

Hahaha, It's cool man. I know how that is.

PerilousActs

01-01-2010, 11:47 PM

Does anyone have any books on suspension to recommend? This could be nice for us suspension noobs to learn from. :) Maybe websites covering the basics?

ballinnmiami240sx

01-02-2010, 06:51 AM

2010 formula D rules state that the subframe can be modded for the exception of one member. What does that mean? They leave it kind vauged for the teams. NASA and SCCA 2010 rule books also do this. Different folks will interprit the rules the way they want. In any type of motorsport "Teams WIll Find an advantage" if there is not a rule. Thats why every year the rules have to be updated. Now there are ofcourse exception to any of these rules. Grandfathered laws and hate to say this but money.

I would think people want to build a track car following the latest rule books. Just makes sense!!!!

Carbomb

01-02-2010, 11:06 AM

Does anyone have any books on suspension to recommend? This could be nice for us suspension noobs to learn from. :) Maybe websites covering the basics?

How to make your car handle by fred puhn

Amazon.com: How to Make Your Car Handle (0075478000012): Fred Puhn: Books (http://www.amazon.com/How-Make-Your-Car-Handle/dp/0912656468)
I GOT THIS GIVING TO ME BY A FORMULA D TECH GUY.
GREAT BOOK

Home (http://dangdrifters.com/default.aspx) DECENT SITE ON ANGLE

Jonnie Fraz

01-02-2010, 11:22 AM

Hahaha, so how does that make sense? The pickup points can't be modified, but then they can?

Pretty dumb.

Clearly the front pickups were modified on the JIC S15. They must have got an exception.

Like Mike said the rules last year were allowing modification of the pick up points. It was like 1.5" in all directions if I remember correctly.

The new exception rule states:
8.3.8 Provisions for vehicles with Vehicle Identification numbers 0-129
Competition vehicles with VID numbers 0-129 can opt for exemption from
sections 8.1.1.1, 8.3.1, 8.3.2, 8.3.3, and 8.3.4.
In such case the following is true:
â€¢ Previously approved modifications of the firewall, subframe and
transmission tunnel, as indicted in the vehicles technical record are
allowed.
â€¢ Suspension pick-up points may be moved to within 1â€ of the OEM
location
â€¢ Stock hubs must be used.
â€œPre 130â€ vehicles wishing not to use the 8.3.8 exemption must request a
new VID.

As for the member modification...The way I am interpeting it is that the sub frame may be modified, but can not be compleatly cut in in half, as to retain stock dimentions side to side.
For instance this sub frame...
http://dangdrifters.com/images/dang%20sub.jpg
would be illegal since it had been cut compleatly into three parts and welded back together, but if you did not cut the front plane and just cut out the rack mounting and moved it, then it would be legal.
The only reason I can figure that they went with this is to keep competitors from widening the pick up points.

ManoNegra

01-02-2010, 01:32 PM

Does anyone have any books on suspension to recommend? This could be nice for us suspension noobs to learn from. :) Maybe websites covering the basics?

Borrowed this one from a friend, plan on buying it eventually

Allan Staniforth's Competition Car Suspension: A Practical Handbook

Amazon.com: Competition Car Suspension: A practical handbook (9781844253289): Allan Staniforth: Books (http://www.amazon.com/Competition-Car-Suspension-practical-handbook/dp/1844253287/ref=sr_1_2?ie=UTF8&s=books&qid=1262464177&sr=8-2)

PoorMans180SX

01-02-2010, 01:43 PM

More Formula D rules

Well, that doesn't make it sound so bad.

Carbomb

01-02-2010, 04:04 PM

Like Mike said the rules last year were allowing modification of the pick up points. It was like 1.5" in all directions if I remember correctly.

The new exception rule states:
8.3.8 Provisions for vehicles with Vehicle Identification numbers 0-129
Competition vehicles with VID numbers 0-129 can opt for exemption from
sections 8.1.1.1, 8.3.1, 8.3.2, 8.3.3, and 8.3.4.
In such case the following is true:
• Previously approved modifications of the firewall, subframe and
transmission tunnel, as indicted in the vehicles technical record are
allowed.
• Suspension pick-up points may be moved to within 1” of the OEM
location
• Stock hubs must be used.
“Pre 130” vehicles wishing not to use the 8.3.8 exemption must request a
new VID.

As for the member modification...The way I am interpeting it is that the sub frame may be modified, but can not be compleatly cut in in half, as to retain stock dimentions side to side.
For instance this sub frame...
http://dangdrifters.com/images/dang%20sub.jpg
would be illegal since it had been cut compleatly into three parts and welded back together, but if you did not cut the front plane and just cut out the rack mounting and moved it, then it would be legal.
The only reason I can figure that they went with this is to keep competitors from widening the pick up points.

This is 1 piece I cut the center out and moved it... so it would be "legal" as f last years rules... I think. its sectioned. not fully cut. FYI

ballinnmiami240sx

01-02-2010, 05:15 PM

so you chopped it in 3 peices and welded it back? That would not pass tech in 2010. I dont want to turn this into a rulebook debate. More talk about suspension.

http://gallery.voodoo-people.com/albums/Diverse/S14_frontsuspension.jpg

http://www.s14trackedition.nl/sylvia/images/stories/DSC01824.JPG

Jonnie Fraz

01-03-2010, 12:07 AM

This is 1 piece I cut the center out and moved it... so it would be "legal" as f last years rules... I think. its sectioned. not fully cut. FYI

Not saying it is not great work, just by this years rules it is a no go.

Carbomb

01-03-2010, 12:47 AM

2 pieces... you'll see if you do it...

Jonnie Fraz

01-03-2010, 02:33 AM

If you cut into two as long as the front plane was not cut then you are good to go. In the pic it looks like it was cut into three pieces. Sweet job, and great idea. How did it work out?

I did some major mods on some Ae86 lower control arms today. Added Battle Version adjusters, moved the holes for the TC rods 25mm inboard, built new adjustable sway bar mount, and plated the crap out of them. Should have cost a forture, but he is my sponsored driver.
Now for some pics...
http://i4.photobucket.com/albums/y147/assassin10000/Suspension/FLCA1.jpg
http://i4.photobucket.com/albums/y147/assassin10000/Suspension/FLCA2.jpg
http://i4.photobucket.com/albums/y147/assassin10000/Suspension/FLCA3.jpg
http://i4.photobucket.com/albums/y147/assassin10000/Suspension/FLCA5.jpg

VIPDRFT

01-03-2010, 03:20 AM

How would you adjust the rear roll center on a car that has a RUCA but no RLCA like this?
http://s.ecrater.com/stores/112360/4a8940bfc0737_112360b.jpg
Would you have to modify the knuckle and/or raise the subframe? Thanks.

Steve Lloyd

01-03-2010, 09:03 AM

Couldn't you just alter the mounting point on the struts (custom housings) to raise the spindle. There's already a guy that makes custom housings, but I was thinking you could alter the mounting location to put the spindle wherever you wanted it, and use more minor adjustments on the LCA.

Just a thought...........

240sxScores

01-03-2010, 09:07 AM

^^ I would say raise the subframe.

The upper control arm has a ball joint. So it would be the same as a car with RLCA just flipped upside down.

95KA-Turbo

01-03-2010, 11:19 AM

What kind of car is that?

You can do this for your lower arms (you'll have to weld in some flat metal on the one with a hole in it):

http://i49.tinypic.com/i6jj3r.jpg

It looks like there's another arm on top of the spindle? You would need to correct that as well.

Changing the strut length will just raise the car up higher, which would correct the geometry - but defeat the purpose.

Def

01-03-2010, 12:13 PM

That's similar to an E36/E46 rear suspension(BMW) - most of those guys just raise up the subframe as much as possible and call it good in the rear.

In our cars, the roll center doesn't drop as quickly in the rear as the front, so a huge amount of correction is not needed back there like the front.

slider2828

01-03-2010, 12:22 PM

Awesome thread guys... THose books could be found on google books. Here's a link to one.

How to make your car handle - Google Books (http://books.google.com/books?id=cr4IyD5l1NQC&dq=how+to+make+you+car+handle&printsec=frontcover&source=bn&hl=en&ei=L-5AS5TBHI-isgPnq9TNBA&sa=X&oi=book_result&ct=result&resnum=4&ved=0CBoQ6AEwAw#v=onepage&q=how%20to%20make%20you%20car%20handle&f=false)

ballinnmiami240sx

01-03-2010, 01:04 PM

nice find. Ill have to read that later.

95KA-Turbo

01-03-2010, 02:04 PM

ballinnmiami240sx

01-03-2010, 05:48 PM

someone need to post a stock s13/s14 ride height and lest look at how nissan originally had it.

Otto347

01-03-2010, 11:19 PM

So having it flat in the front and nearly flat in the back is ideal?
Basiclly, you're trying to find a happy medium between squat and anti squat. Then depending on how the weight transfers to the rear tune it for what works for your application.

VIPDRFT

01-03-2010, 11:46 PM

What kind of car is that?

You can do this for your lower arms (you'll have to weld in some flat metal on the one with a hole in it):

It looks like there's another arm on top of the spindle? You would need to correct that as well.

Changing the strut length will just raise the car up higher, which would correct the geometry - but defeat the purpose.

It's a JZX90/100 Toyota Chaser/Cresta/Mark II

I see. Good idea. I hadn't thought of that. That arm on top is the RUCA. I'm still have no idea on how to correct that, besides raising the subframe.

Yeah, I don't want my car having 4x4 status. :P

That's similar to an E36/E46 rear suspension(BMW) - most of those guys just raise up the subframe as much as possible and call it good in the rear.

In our cars, the roll center doesn't drop as quickly in the rear as the front, so a huge amount of correction is not needed back there like the front.

That doesn't surprise me becuase I've heard the JZX-chassis was built to compete with the BMW sedans. Would I just use subframe spacers like Parts Shop Max makes for th S-chassis?

Good to know. Thanks.

white92_s13

01-04-2010, 01:53 AM

ok so this thread inspired me! I had a spare set of knuckles and lower control arms. I took some 1/8th" plate i had and cut it out cleaned it up and boxed the lower control arm. need to weld one more plate on to add some more strength. Then i did some research on Knuckle modification

P/s knuckle TOP and NON p/s knuckle Bottom
http://www.club4ag.com/faq_and_tech_pages/Tech%20Photos/AE-86_steering_arms.jpg

These are the "D1 SUPER ANGLE" modified shortened stock p/s knuckles! SHORT!!!!
http://www.musclebear.jp/images/original02.png

Anyways I have a friend with a good welder and a oxy acetylene torch and we can heat them up and weld it up nice! Im going to post more pictures of them modified tomorrow!

Sonic Motor

01-04-2010, 02:16 AM

great thread. All newbie drifts looking to setup their suspension for drifting, look here first!
Me thinks this should be sticky in Motorsport forum or something.

thanks for posting this!

lflkajfj12123

01-04-2010, 02:50 AM

SoSideways

01-04-2010, 01:14 PM

you definitely don't need to modify suspension pick up points or steering angle or even give a shit about roll center to do drifting

90% of the people looking to do these mods still don't have the driver skill to require them

See...

You're a cool dude, but honestly, everytime someone tries to talk technical stuffs, you spew that crap out...

Fixing the roll center will allow the car to corner flatter, especially the front, so instead of running like 15k springs up front and a 50mm sway bar, you can run 8k springs and stock sway bars and have the car stay mostly flat. How does that require more skills to notice?

Even BH noticed his car rolls a bit much during drifts, and it shows on the banner pic on his blog.

He has said that he doesn't care about it, so that's cool, it's up to him how he wants to setup his car (although he has said he wanted to buy Tanabe sways to remedy that situation), but he doesn't come onto any of the roll center and other technical discussion threads and tell how everyone sucks at driving and they shouldn't care.

Geez dude.

BTW thanks for uploading Video Option Vol 81 on youtube. That's the one with the Stinger team. Appreciate it!

Steve Lloyd

01-04-2010, 01:26 PM

SoSideways

01-04-2010, 01:39 PM

^ For which application?

Oh hey I just realized it you man, how's it going?

mmdb

01-04-2010, 02:35 PM

you definitely don't need to modify suspension pick up points or steering angle or even give a shit about roll center to do drifting

90% of the people looking to do these mods still don't have the driver skill to require them

You might not feel the difference. That's probably cause you're too busy struggling to shove your elbow into the door sill to prop yourself to see over the dash as you car is riding on two wheels through any corner.

J/k J/k. Anyway, all kidding aside. I'd put modifying roll center up there with adding a sway bar or stiffer springs. It's makes a huge difference.

PoorMans180SX

01-04-2010, 02:49 PM

So having it flat in the front and nearly flat in the back is ideal?

Basically you want it just under your center of gravity. I think what Def is saying is that the rear arms don't need to be corrected as much because they don't go to such extreme angles like the front ones do.

I'm pretty sure having both front and rear angled slightly up is ideal. The center of gravity on these cars is pretty low, but not low enough to warrant flat arms.

Anyone can feel free to correct me if I'm wrong. I'll edit this post afterward. The reason I edit my posts is because I don't want to have any misinformation in this thead. Sometimes people don't read through things all the way and get the wrong ideas, and I don't want that happening here.

you definitely don't need to modify suspension pick up points or steering angle or even give a shit about roll center to do drifting

90% of the people looking to do these mods still don't have the driver skill to require them

SoSideways said it already, but we know this. I think what carparthookup was saying was that the newbies should check this stuff out first, because bottom line, your car will function better with these kind of suspension setups.

It doesn't take any more skill to use a better-functioning suspension.

I can see what you're saying about the angle mods, because they DO take more skill to use.

GripTerror

01-04-2010, 02:54 PM

Keep the stupid comments to the minimum gentlemen :) So far this thread kicks ass :D I wish driftworks would respond i contacted them with questions but no response yet

PoorMans180SX

01-04-2010, 02:55 PM

Am I way off base here?? I'm getting ready to make my own coilover setup and would like some feedback.............

Yeah bro. All you're doing by making custom damper housings is using a longer shock. There is no way to correct your roll center/suspension movement using coilovers, besides riding like a 4x4.

mmdb

01-04-2010, 02:57 PM

PoorMans180SX

01-04-2010, 03:02 PM

PoorMans180SX

01-04-2010, 03:17 PM

I'm currently communicating with Ben from Driftworks concerning his rear knuckles. So far this is what I know.
1. they won't modify their design to work with the z32 rear fork type
2. custom roll center adjustment is a NO and will remain fixed at the height listed.

I got a few more questions asked and I'll post 'em up as I get answers.

On number two, you can't really go a whole lot farther otherwise you interfere with the axle boot. This is the what Dan from Parts Shop MAX has to say about it:

The limiting factor of how much we can raise the spindle to drop the car seems to be the interaction between the RUCA arm and the axle boot.
Our current RUCA arm is upswept already especially designed for lowered cars so if you even try to do a drop spindle on someone elses RUCA your pretty much [email protected]

http://i24.photobucket.com/albums/c25/Turbo711/MAXRUCA.jpg

we disconnected the coilover and jacked up the wheel all the way to take a look at the most extreme clearance situation:

http://i24.photobucket.com/albums/c25/Turbo711/wheeljack.jpg

http://i24.photobucket.com/albums/c25/Turbo711/1246407673_2_FT0_p1040829.jpg

And then we put it back to a normal suspension compression and measured again

http://i24.photobucket.com/albums/c25/Turbo711/Normalwheel.jpg

http://i24.photobucket.com/albums/c25/Turbo711/measure.jpg

It seems like 3/4" drop spindle is the happy medium because it looks like half an inch is totally safe and 1 inch is the max.
with the half inch subframe risers its already a big difference so this should be a great mod for suspension performance on extra low cars.

If we wanted to take it farther we would have to sweep the arm up on the RUCA more or get a custom slim boot for the axle, but I'm betting as is its going to make a huge difference without going any farther.

GripTerror

01-04-2010, 03:24 PM

CrimsonRockett

01-04-2010, 03:28 PM

Don't fuck up another thread by making useless posts.

Fair warning to everybody.

mmdb

01-04-2010, 03:31 PM

shit that means ill have to mod my shocks to be stock s13 bushing type not z32 fork type........

what about spherical bearings as opposed to polyurethane ones...

I'm not sure... I asked them if OEM ones had the same diameter of the stock ones. In that case you should be able to use Def's spherical bearings. I'll talk to my local fab shop to modify the knuckles if I get them. I asked a few details about their knuckle's geometry in the rear... that's most important.

GripTerror

01-04-2010, 03:35 PM

ya i already got def's sphericals in the rear... i dun think i can just press them out lol... and reuse them.. they'll be fubared by the time i take them out hahaha... it would just be less of a pain in the ass if they had an option with them already... seriously... but oh well.

ManoNegra

01-04-2010, 03:39 PM

I'm not sure... I asked them if OEM ones had the same diameter of the stock ones. In that case you should be able to use Def's spherical bearings. I'll talk to my local fab shop to modify the knuckles if I get them. I asked a few details about their knuckle's geometry in the rear... that's most important.

I'm curious about that aswell

ya i already got def's sphericals in the rear... i dun think i can just press them out lol... and reuse them.. they'll be fubared by the time i take them out hahaha... it would just be less of a pain in the ass if they had an option with them already... seriously... but oh well.

that is likely to be the case, it's what happened to the ones we took out while making adjustments.

Teknolust72

01-04-2010, 04:36 PM

ManoNegra

01-04-2010, 04:59 PM

If you are using a modified drop spindle in the rear, would there even be an extra benefit to using Z32 rear fork?

My first thought is that it wouldnt matter at all, but if someone knows, please enlighten me.....

There wouldn't from a user point of view.
There would from a manufacturing one though, it's easier by far make to make an upright that utilizes a fork style mount IMO.

mmdb

01-04-2010, 05:04 PM

If you are using a modified drop spindle in the rear, would there even be an extra benefit to using Z32 rear fork?

My first thought is that it wouldnt matter at all, but if someone knows, please enlighten me.....

There is no real benefit using one type or another, but the reason why some of us have the fork type is because we're using the z32 rear aluminum spindles to save UNSPRUNG weight.

GripTerror

01-04-2010, 05:09 PM

8lbs per corner if I'm not mistaken. It's significantly lighter just by feel... its a no brainer.

Edit: Aluminum vs iron no brainer :hahano:

Teknolust72

01-04-2010, 05:17 PM

There is no real benefit using one type or another, but the reason why some of us have the fork type is because we're using the z32 rear aluminum spindles to save UNSPRUNG weight.

Oh ok, thats what I thought. I know Kawabata's GP Sports 180SX uses BNR34 rear spindles for weight savings too, but I thought there was some other "black magic" going on under there....lol

Anyway, I wanted to share with you guys this scan from Doriten of the modified rear spindles that Team Evolution uses on their cars:

http://i15.photobucket.com/albums/a369/Teknolust72/EvolutionKnuckle.jpg

I noticed the toe arm position being moved; does the Driftworks one do that too?

If someone wants the hi-res/4mb file, I can email it.

GripTerror

01-04-2010, 05:18 PM

we need engrish translat0rz

PoorMans180SX

01-04-2010, 05:24 PM

Oh ok, thats what I thought. I know Kawabata's GP Sports 180SX uses BNR34 rear spindles for weight savings too, but I thought there was some other "black magic" going on under there....lol

Anyway, I wanted to share with you guys this scan from Doriten of the modified rear spindles that Team Evolution uses on their cars:

I noticed the toe arm position being moved; does the Driftworks one do that too?

If someone wants the hi-res/4mb file, I can email it.

What they're doing there is the same thing the JIC team (and that S15 that KA-turbo posted) does. They're cutting off the toe and coilover mount and re-welding them lower. This makes the toe arm parallel with the lower control arm and corrects your toe curve when really low.

I think they move the coilover mount just so they don't have to max out the lowness on the coilover.

The lower control arm ball joint might be a little lower there too. This would correct roll center a hair.

Just a side note, but that lower control arm that they "made" looks janky.

PoorMans180SX

01-04-2010, 05:38 PM

Also, if someone actually made aluminum drop knuckles, it would probably be the coolest thing ever.

They would also probably cost a ridiculous amount of money.

So much so that I would probably just buy steel. I'm guessing the driftworks ones are a little lighter than stock anyway.

GripTerror

01-04-2010, 06:02 PM

PoorMans180SX

01-04-2010, 06:03 PM

jholman05

01-04-2010, 07:40 PM

Someone tell me if this sounds stupid. For the longest time now, I've been wanting to do z32 knuckles, get the stance lower sleeve for the z32's and upgrade my gr+ to gr+ pro, with the addition of the tender or "helper" spring. Also lately I've been wanting to go with the s14 subframe, but find it cumbersome to change my diff cover, find the metal offset bushings, deal with my 17x10 +22 with 275/40/17 being pushed out 5mm (s14 subframe being wider) or whatever and not adding more camber.

Does anyone know if you could carefully cut the s14 front rlca mounts off the s14 subframe, and cut the s13's off and weld the s14 mounts on the s13 subframe? To me this sounds easier than dicking with the entire s14 subframe. Or just welding tabs on myself and not even buy a s14 subframe.

Pros
-So I don't want a wider subframe becuase I'm already close on clearance with the wheels/tires with a roll and pull
-Don't want to buy more expensive offset subframe bushigns
-Have a super clean s13 subframe
-Keep my diff cover
-Keep my exhuast hanger location

Cons
-fabbing the tabs for the rlca

Also what subframe bushings does everyone recommend? I'm looking for most overall grip with little concern about noise or vibration. I've tried mmr-direct but ehh not sure if I like them, I dont think it retained factory anti-squat.

-PSM
-SPL
-Nismo
-MMR
-Oem filled or collared

Sorry if this seems just thrown out there, my mind is scrambled.

Jonnie Fraz

01-04-2010, 08:28 PM

ballinnmiami240sx

01-04-2010, 08:33 PM

you just scrambled mine with that post..lol

If I gather your post correctly you want to make new mounts in the rear subframe to except s14 rlca's on to your s13 subframe but at the same location?

Arnt the rlca's the same. I had them side by side and they are almost identical. One has more metal than the other, but Im pretty sure they mount the same. Please correct me if Im wrong. I just had them at the shop side by side, but didnt actually measure them.

Or are you taking about the RLCA's mounting location at the subframe in refrence to the s14 vs. s13 subframes. I wouldnt dick with the mounting points on the subframe. I just dont really understand your reason.

ballinnmiami240sx

01-04-2010, 08:46 PM

Well they should offer an aluminum and spherical option... especially when some of us are interseted in extracting maximum performance. I mean correcting geometry is a bigger pro/gain than anything else for the most part... but going back to something that potentially heavier and binding (polyurethane) is not cool. As mmdb said though we COULD make/buy alternatively sphericals as he and I already have... but why not have a product already with that err..

And why should it be automatically 'expensive', that sounds stupid. If Nissan could bring both on a factory car, an aftermarket one should be available with little to no difference equally.

At the end of the day all we're getting is the effort of someone else who figured out how to move these points and then cast/forge/put together magically with their choice of metal/material. A. Because alot of us dont have the knowledge B. Don't have the connections.

That being said, just because its aluminum doesnt mean that it should cost automatically more on the price. Think about it... The s13 and z32 spindles are not that different just different material and fork vs bushing type. They are overall the same shit.

So true....things dont have to be expensive. i remember when there where like two people selling knuckle.....$499 + shipping. Alot of us got smart and decided there is no way it could cost that much to cut and reweld something and started making our own sets. Now they are selling at half that price because people caught on. If you are left with one company supplying a product then that company can set any price. I would think if it the product was afforable then you would make more money from quantity alone.

We all agree the rear knuckles need to be modified to correct the geometry, but no one on this board can tell you what ride height they will be running tomorrow. To sale or make a product on what if's will be kind of a waste with out adjustability. I for one run my car super low with the arms facing the sky and still managed to drive the living hell out of my car. Im I going to correct this YES!!! Making a drop spindle would help correct most of the problem.

jholman05

01-04-2010, 09:36 PM

Jonnie I was under the impression PBM - PSM were the same company?

Or are you taking about the RLCA's mounting location at the subframe in refrence to the s14 vs. s13 subframes. I wouldnt dick with the mounting points on the subframe. I just dont really understand your reason.

That ^, basically move the rlca mounts on my s13 subframe to match that of an s14.

I come from a mini trucker/air ride back ground. I've chopped my whole frame in half and welded it back together, I think I can handle a couple little mounting tabs. Also I just pretty much totaled the front of my car and I'm in the process of replacing most everything in front of the firewall. I'd post pictures, but I don't want to clutter the thread.

Also I don't care about any rules, I just like to work on stuff. Then see if it had any improvements.

95KA-Turbo

01-04-2010, 10:46 PM

If you're going to copy a subframe you might as well copy the S15 subframe, since it's better then the S14 one. I honestly am not sure what makes it better, or even what the differences are between the S13 and S14 rear subframes.

GripTerror

01-04-2010, 11:20 PM

the s14 and s15 subframes are identical, to the exception of the fact that the s15 subframes are better/more braced. That is all.

Jonnie Fraz

01-04-2010, 11:55 PM

Jonnie I was under the impression PBM - PSM were the same company?

That ^, basically move the rlca mounts on my s13 subframe to match that of an s14.

Correct...They are the same. Sorry, my thought is S13 sub frame vrs S14 sub frame how much higher are the pivot points. The PSM inserts move the subframe up approx .5" how much higher would you want to move it?
If you look at the PSM rear subframe they moved theirs up a bit, I would say like 2" judging by the pics.

mmdb

01-05-2010, 09:09 AM

Called Ben over at driftworks. Here's more info passed down:
- the rear spindles do not keep exact stock geometry, but keeps the geometry as close as stock as possible to retain dynamic alignment settings from factory.
- the diameter of the pivot bushings are not the same as stock. This was due to the design changes required to develop the knuckle so no more usage of Def's spherical bearings.
- the front spindle's kingpin angle has changed.
- z32 rear e-brake will be a OK.

GripTerror

01-05-2010, 10:31 AM

mmdb

01-05-2010, 10:49 AM

Eh so never mind def's sphericals all together then..

so did he say if theyll offer a spherical option?

What about the front i am still confused about the whole extra steering angle ordeal, I dont wana drift thatll be a problem when tracking the car lol... well in grip not drift.

They're being a bit slow to respond with all the questions they should have an faq :-/

Nope. No spherical options as they thought a large portion of the folks wouldn't want them. I forgot to ask about ackerman for the front spindles... I'll ask whenever they get back to me via email... but like you said... they're pretty damn slow or maybe our emails aren't getting through to their firewall.

kognition

01-05-2010, 10:52 AM

It could ruin your day on the track. Too much turn in grip isn't good. Because it's so easy to turn just a couple degrees over and the next thing is you are ice skating in a turn.

Eh so never mind def's sphericals all together then..

so did he say if theyll offer a spherical option?

What about the front i am still confused about the whole extra steering angle ordeal, I dont wana drift thatll be a problem when tracking the car lol... well in grip not drift.

They're being a bit slow to respond with all the questions they should have an faq :-/

mmdb

01-05-2010, 11:05 AM

It could ruin your day on the track. Too much turn in grip isn't good. Because it's so easy to turn just a couple degrees over and the next thing is you are ice skating in a turn.

Are you referring to the nature of modifying the roll center so much that it suddenly overloads the tire causing abrupt under and/or oversteer? I noticed that when I added 35mm of adjustment on my gp sports knuckles... Tires did not like it one bit during turn in. Sudden understeer.

PoorMans180SX

01-05-2010, 12:28 PM

And why should it be automatically 'expensive', that sounds stupid. If Nissan could bring both on a factory car, an aftermarket one should be available with little to no difference equally.

I'm sorry, I was thinking of someone CNCing aluminum drop spindles. Clearly this would cost more than making a jig and welding steel plates together.

Does anyone know if you could carefully cut the s14 front rlca mounts off the s14 subframe, and cut the s13's off and weld the s14 mounts on the s13 subframe? To me this sounds easier than dicking with the entire s14 subframe. Or just welding tabs on myself and not even buy a s14 subframe.

Also what subframe bushings does everyone recommend? I'm looking for most overall grip with little concern about noise or vibration. I've tried mmr-direct but ehh not sure if I like them, I dont think it retained factory anti-squat.

Yes, you can modify the S13 subframe to be like a S14 subframe. It's completely safe. What this does is change the squat. The S14 subframe has more squat because of the flatter angle of the LCA. You can actually just modify the S13 subframe, no need to buy an S14 one. However, it may not meet tech in some racing classes.

This is what Parts Shop MAX did on their S13. It's the orange subframe in the first post. They actually moved their pivot points farther up, giving a lot of squat and traction.

Parts Shop MAX and SPL both make great subframe bushings. SPL's can either be set to stock, or made to raise the subframe like the PSM ones do.

- the front spindle's kingpin angle has changed.

For those that don't understand, If you project a line from your top pillowball through to the bottom balljoint, then measure the angle between that line and true vertical. That's your kingpin inclination. Driftworks did this because it helps keep your wheel upright with extreme angles.

On anther subject, the Parts Shop MAX spindle is supposed to be 100% Machined. This means it would be fairly easy to make an aluminum one. There's the aluminum/spherical combo you've been looking for. Maybe I'm misunderstanding, but Here's what Dan said:

We are jigging up for some rear knuckles.
Planned features:
~100% machined steel - no casting components
~drop spindle
~pillowball replacements for all bushings
~improved strength
~independent hydrobrake caliper bracket

jholman05

01-05-2010, 01:15 PM

Yes, you can modify the S13 subframe to be like a S14 subframe. It's completely safe. What this does is change the squat. The S14 subframe has more squat because of the flatter angle of the LCA. You can actually just modify the S13 subframe, no need to buy an S14 one. However, it may not meet tech in some racing classes.

This is what Parts Shop MAX did on their S13. It's the orange subframe in the first post. They actually moved their pivot points farther up, giving a lot of squat and traction.

Parts Shop MAX and SPL both make great subframe bushings. SPL's can either be set to stock, or made to raise the subframe like the PSM ones do.

Well that's what I think I'll do then, seems easier to me than with everything else. I'll be ordering either the PSM or SPL subframe bushings soon, as well as the coilover sleeves for the z32 knuckles.

Now can someone post up a few good pictures of the s14 rlca subframe mounts so I can copy them on my s13 subframe? I tried lookin on google images but wasnt getting anything worth a damn.

ManoNegra

01-05-2010, 01:30 PM

I'm sorry, I was thinking of someone CNCing aluminum drop spindles. Clearly this would cost more than making a jig and welding steel plates together.

If you make it a one piece unit, it would be very difficult to machine since it
would most likely require a 5 or 7 axis machine to make them.
I think a modular assembly similar to the griggs one for mustangs is the way to go.
One piece to locate the strut and hub
one piece to locate the brake caliper.
One piece to locate the LCA balljoint and tie rod.

Machining it as a three parts assembly makes it a whole lot easier and would
bring the cost down significantly.
There is also a great deal of freedom in the design:
You need more (or less) roll center correction? Easy, just unbolt the lower part and bolt in a new one.
You want to run Evo, STi or whatever brake caliper without adapter brackets. Sure, just unbolt the stock piece and put a new one.

Yes, you can modify the S13 subframe to be like a S14 subframe. It's completely safe. What this does is change the squat. The S14 subframe has more squat because of the flatter angle of the LCA. You can actually just modify the S13 subframe, no need to buy an S14 one. However, it may not meet tech in some racing classes.

This is what Parts Shop MAX did on their S13. It's the orange subframe in the first post. They actually moved their pivot points farther up, giving a lot of squat and traction.

Parts Shop MAX and SPL both make great subframe bushings. SPL's can either be set to stock, or made to raise the subframe like the PSM ones do.

Best solution I have heard is this:
A set of solid aluminum bushings that raises the subframe,
allows to install S14 subframes into S13
and enhances the geometry, ie: maybe adds some caster, fixes the z32 upright shock binding issue in S14s, etc.

On anther subject, the Parts Shop MAX spindle is supposed to be 100% Machined. This means it would be fairly easy to make an aluminum one. There's the aluminum/spherical combo you've been looking for. Maybe I'm misunderstanding, but Here's what Dan said:

So machined steel parts but still welded on a jig?
My concern about doing it this way with aluminum is that it's difficult to get
good penetration and retain strength with aluminum.
It would require a lot of heat to get good welds and aluminum tends to distort at high temperatures.

PoorMans180SX

01-05-2010, 03:25 PM

Now can someone post up a few good pictures of the s14 rlca subframe mounts so I can copy them on my s13 subframe? I tried lookin on google images but wasnt getting anything worth a damn.

Here you go (S15). You can see that the front mounts are lower:
http://i24.photobucket.com/albums/c25/Turbo711/SubframeS15.jpg

If you make it a one piece unit, it would be very difficult to machine since it
would most likely require a 5 or 7 axis machine to make them.
I think a modular assembly similar to the griggs one for mustangs is the way to go.
One piece to locate the strut and hub
one piece to locate the brake caliper.
One piece to locate the LCA balljoint and tie rod

I wasn't even thinking of this. Definitely would be the way to go.

So machined steel parts but still welded on a jig?
My concern about doing it this way with aluminum is that it's difficult to get
good penetration and retain strength with aluminum.
It would require a lot of heat to get good welds and aluminum tends to distort at high temperatures.

Ah, this makes more sense.

ballinnmiami240sx

01-05-2010, 04:46 PM

ManoNegra hit it on the head. Making something for mass production that will work for everyone would require what he stated. It would allow the nissan community to have something it has never had.

IE.

http://www.performanceautosport.com/images/cars/GT500Blue%2043%20800.jpg

http://www.griggsracing.com/images/S197SPINDLE.jpg

The advantage of this would be people could buy a knuckle that was aluminum, strong, and adjustable to what ever angle, ackerman, and roll center you wanted. Beleive me that this picture has been in my head for about 6 months now. I dont have access full time to a machine shop, but if I did this would be the first thing i would make.

This griggs front spindle set up it offered to the mustang road racers at a prices of $2999.95. Way more than the 240 owner would ever pay. Why can griggs do this? Well they have patents pending on that desing and are the only ones as far as i know that make something like this for the stang. I passed something like this thru stephen "95ka-turbo's head and my idea was to try to figure a way to have a 6160 billet aluminum boltable tierod piece that we could all use. This will solve bumpsteer issues and have multiple pre lenght outer tierod mounting points for "X" angle.
http://www.bradscustomauto.com/catalog/images/manufacturers/Griggs/MDS4000.jpg

ManoNegra

01-05-2010, 05:12 PM

I don't know what you mean here. Caster has little affect on the rear suspension, and putting an S14 subframe in an S13 is going to make your Z32 shocks fit worse.

To clarify, a well designed set of solid subframe bushings could possibly correct the problem with Z32 upright/S14 subframe binding that traditionally occurs by altering the location of the subframe.
But only by doing some R&D can we know for certain.

GripTerror

01-05-2010, 05:38 PM

^SPL just released offset subframe bushings!

FYI you can fit S14/S15 subframe now into S13:

http://www.splparts.com/main4/parts/NissanShared/Suspension/Subframe/SPLSSBS13_C.jpg

Our CNC machined T6061 aluminum subframe bushings completely replace the stock bushings to eliminate free play of the subframe relative to the chassis, reducing wheel hop and improving suspension performance. Our new version 2 solid subframe bushings is designed to allow the subframe to sit up to 1/2" closer to the chassis (raising the subframe), which will allow up to 1/2" compensation of roll center for a lowered car.

However raising the subframe will not just change roll center, it will also increase anti-squat. Therefore our subframe bushings include 1/4" slide in shims so you can quickly raise or lower the subframe in minutes, and adjust the roll center and anti-squat behavior to best fit your driving style! Our unique adjustable subframe bushings offer a completely new way to tune the suspension behavior.

Available in standard (S13 subframe onto S13 chassis, or S14/S15 subframe onto S14/S15 chassis) or offset (S14/S15 subframe onto S13 chassis or vice versa).

ballinnmiami240sx

01-05-2010, 05:44 PM

outstanding!!!!! spl has always been in the fore front of development. Now someone link Kuah to this thread, so they can start making something.

longfellow

01-05-2010, 05:54 PM

I don't know what you mean here. Caster has little affect on the rear suspension, and putting an S14 subframe in an S13 is going to make your Z32 shocks fit worse.

Caster has a huge affect on the rear suspension. Changing the rear traction rods length greatly affects the camber curve in the rear.

The reason Z32 uprights fit like shit in an S14 is because the shot is alot longer and run at a different angle from the uppeer mount. Z32 and S13 shocks are almost the same length. Changing subframes dosnt really do anything in relation to how the shock mounts.

PoorMans180SX

01-06-2010, 01:27 PM

Caster has a huge affect on the rear suspension. Changing the rear traction rods length greatly affects the camber curve in the rear.

The reason Z32 uprights fit like shit in an S14 is because the shot is alot longer and run at a different angle from the uppeer mount. Z32 and S13 shocks are almost the same length. Changing subframes dosnt really do anything in relation to how the shock mounts.

:facepalm: Deleted that post. Don't know what I was thinking.

I'm thinking about doing some serious editing to the first posts to include more technical information on the front and rear suspension.

Again, thanks to everyone who is contributing, I think we have some awesome stuff going on here, and I'm definitely enjoying the learning!

I PMed Kuah the link to this thread.

mmdb

01-06-2010, 02:32 PM

kalypso123

01-07-2010, 12:38 AM

thread subscribed and bookmarked

Def

01-07-2010, 11:06 AM

Some more Driftwork info:
- installation is bolt on affair.
- knuckles are ensured to be very, very strong (I asked cause I wanted to use these on the road)
- offset spacers will be available end of January, 2010
- knuckles were designed with road racing geometry in mind. I understood this as the camber, toe, etc gains/losses remain as OEM as possible
- for road racing usage without the spacers are recommended, drift use the spacers.
- if using them for road racing purposes without the offset spacer, usage of a stock length tie road (inner and outer) maybe not be long enough. Brands such as SPL Parts/Kazama would be preferred.
- the knuckles are currently available.
- ... will post up more as I come across it.

With that said, anyone interested in a set of GP Sport Hyper Knuckles with 20mm spacer adjustments so I can try the Driftworks knuckles out? LMK :)

So I've just got to ask. Why is everybody wanting geometry to "be like stock?"

The bumpsteer isn't bad in the rear when you lower the car, and there are a couple of ways to get the roll center back up to a reasonable height. Besides, stock geometry via a heavily revised drop spindle with a severely lowered car will probably put the roll center ABOVE the CG - which is something you don't want.

Just wanting to know if there's any real justification behind this other than "I guess stock must be the best."

kognition

01-07-2010, 11:49 AM

No, i meant that when you are at certain speed and turning angle going into a corner, that the grip stops gripping, then you are ice skating straight into the gravel. So too much turning angle would not be good, unless you are a pro and can control your reflexes.

Are you referring to the nature of modifying the roll center so much that it suddenly overloads the tire causing abrupt under and/or oversteer? I noticed that when I added 35mm of adjustment on my gp sports knuckles... Tires did not like it one bit during turn in. Sudden understeer.

mmdb

01-07-2010, 11:52 AM

That's a good point. Definitely don't want the roll center to be above the CG. I'm personally still bouncing the idea of using driftwork spindles in my head. Without the knowledge of where the true CG is or the RC is then it's pointless to purchase these units. I'll try to get get some measurements done this week to get a general height/location of the roll center this weekend.

In my experience, when I had about 50mm of front adjustment, the roll center was most likely to be TOO high. At the time I was running an 18" wheel with a 265/35 tires on there and I was get SUDDEN understeer during turn in. I remain a bit skeptical of how much roll center adjustment is needed, but the other side of me tells me there's only one way to find out. But of course there's a few steps to get to check whether or not it's needed.

No, i meant that when you are at certain speed and turning angle going into a corner, that the grip stops gripping, then you are ice skating straight into the gravel. So too much turning angle would not be good, unless you are a pro and can control your reflexes.

Oh gotcha. Currently, as my car gets closer to the limit the fronts initially scream which is safer rather than have the rear slide out first. At that point it's nice to have adjustable sway bars to tweak and tune the rotation of the car to prevent front from washing out.

PoorMans180SX

01-08-2010, 10:23 AM

Original post edited. Let me know if I missed something or said something wrong.

longfellow

01-08-2010, 10:43 AM

:facepalm: Deleted that post. Don't know what I was thinking.

I'm thinking about doing some serious editing to the first posts to include more technical information on the front and rear suspension.

Again, thanks to everyone who is contributing, I think we have some awesome stuff going on here, and I'm definitely enjoying the learning!

I PMed Kuah the link to this thread.

Haha no worries, if you get the S13 and S14 FSM's go into the body section and it will give you measurements for the chassis itself and I think it might cover the subframes but I cant remember. That kinda helps in relation to over geometry for the chassis and suspension.

I know from experience about the S14/Z32 set up because its on my car right now. I kinda regret doing it and sadly I tossed my stock uprights. For an S14 its not really worth the effort unless you can cut the shock mount off and relocate it so it dosnt sit at such a terrible angle. I've already torn my Nismo shock bushing. Spherical bearing would help some but the mounting bracket for the coil-over actually hits the upright and there isnt much you can do about it.

So I suggest to people with S14's to not do Z32 uprights unless you want to figure out how to re-work the mounts.

Def

01-08-2010, 11:52 AM

Haha no worries, if you get the S13 and S14 FSM's go into the body section and it will give you measurements for the chassis itself and I think it might cover the subframes but I cant remember. That kinda helps in relation to over geometry for the chassis and suspension.

I know from experience about the S14/Z32 set up because its on my car right now. I kinda regret doing it and sadly I tossed my stock uprights. For an S14 its not really worth the effort unless you can cut the shock mount off and relocate it so it dosnt sit at such a terrible angle. I've already torn my Nismo shock bushing. Spherical bearing would help some but the mounting bracket for the coil-over actually hits the upright and there isnt much you can do about it.

So I suggest to people with S14's to not do Z32 uprights unless you want to figure out how to re-work the mounts.

You just need some slight clearancing of the shock mount on the upright with spherical bearings to keep from getting contact from what I hear.

longfellow

01-08-2010, 11:57 AM

With any type of rubber bushing thats pretty much out of the question, I had to grind down part of my shock mount and the coilover bracket to get it to where it wouldnt hit. Also the lower the car is the worse the angle gets.

I was hoping the Sphericals would make the difference. But I'm not going to find out first hand because there a better solution. KW V3's

On a new note, Is there any measurements that would be a good idea to take when I shave my subframe bushings? I plan on bring the subframe pretty much directly to the frame with maybe a 1/16" shim. I also plan on making a few shims in difference sizes so I can raise and lower the subframe up to 1/2 like the SPL kit.

nissankat

01-08-2010, 03:55 PM

ballinnmiami240sx

01-08-2010, 04:05 PM

I just installed a set of these on a buddies car and the z32 rear to shock mount is horrible. It does weight a ton less!!!!!

GripTerror

01-08-2010, 05:46 PM

95KA-Turbo

01-08-2010, 05:58 PM

Yeah, when I get the car moving I am going to get the rear shock mount cut and welded so it will be at the right angle when I get the toe arm mount corrected.

Def

01-08-2010, 06:09 PM

^^ The sphericals will not solve the problem. I was running the spl sphericals in the z32 knuckles on my s14 and they would still bind under compression. They actually bent the mounts on the bottom of the coilovers and caused one of the shocks to blow. My car handled so much better after getting rid of the z32 knuckles and eliminating the bind.

They need a smaller diameter misalignment bushing, and then some clearancing on the spindle.

You save a little over 6 lbs per side going with Z32 rear spindles over stock iron ones.

GripTerror

01-08-2010, 06:18 PM

i believe when i had it on scale it was 8lbs.. but whatever 6-8... either way incredible unsprung savings !

longfellow

01-08-2010, 06:25 PM

Basically the bottom line benefit of running z32 spindle IS weight loss and that's 8lbs PER corner. Which is frickin awesome. Imagine people bickering about wheels weighing 1lb up and down... put that into perspective.

Wheels create centrifical inertia, 1lb extra rotating is alot different than 1lb going up and down a few inch's. So saveing 1lb per wheel is a huge gain. It affects the suspension movement, gearing, braking and turning. Which is alot more to consider.

So put that into perspective.

And I restate that if you have an S14 its not worth the aggervation to run Z32 uprights. I plan on switching back to stock uprights as soon as I can find some.