This is the roll center, suspension pickup, and steering angle modification thread. - Page 252 - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Motary · 12-30-2017, 10:47 AM

Quote:

Originally Posted by PoorMans180SX

You can run any stock length control arm then. GKtech, PSM, or whatever. GKtech has the most clearance, but you'll run into your sway bar. Not that you'll have to worry about trailing wheel clearance if you're on stock knuckles.

Stock rear LCA's are fine depending on how hard you drive the car/how much traction and power it has.

With GKtech rear knuckles, you should modify your RLCA front pickup, putting it where the S14's is. I'm going to assume your car is not very low because you have fender liners, and your anti-squat will be through the roof on an S13 that's not slammed.

Anti-squat can be lessened by lengthening the traction arm, coilover clearance from axle boot must be taken into account

e30gangsta · 12-30-2017, 10:15 PM

Quote:

Originally Posted by PoorMans180SX

You can run any stock length control arm then. GKtech, PSM, or whatever. GKtech has the most clearance, but you'll run into your sway bar. Not that you'll have to worry about trailing wheel clearance if you're on stock knuckles.

Stock rear LCA's are fine depending on how hard you drive the car/how much traction and power it has.

With GKtech rear knuckles, you should modify your RLCA front pickup, putting it where the S14's is. I'm going to assume your car is not very low because you have fender liners, and your anti-squat will be through the roof on an S13 that's not slammed.

Got it car is lowered and on 15's I wouldn't consider it slammed but its low lol. Car makes 350rwhp nothing out of this world, eventually it will go jz. Hence why I bought the knuckles/dual caliper option.

As for modifying the stock rcla, I assume stock s14 rlca do not bolt up to an s13? Now I'm curious if I should just upgrade to an s14 rear subframe due to the knuckles/anti squat benefits.

McRussellPants · 12-31-2017, 10:09 PM

Quote:

Originally Posted by Motary

Anti-squat can be lessened by lengthening the traction arm, coilover clearance from axle boot must be taken into account

Do you actually lessen your anti squat % or just lessen your anti % loss over travel though?

Motary · 01-04-2018, 06:38 AM

Quote:

Originally Posted by McRussellPants

Do you actually lessen your anti squat % or just lessen your anti % loss over travel though?

Actual anti-squat, the side view instant center is changed as the knuckle rotates and height from ground changes.

da_crew10 · 01-04-2018, 02:53 PM

Question Maybe MOTARY can shimmy in: I am looking into the GKTech knuckle adapters that provide 40mm of correction which should be more than enough with my current set up. I just have a few questions if anyone has any experience with these.

Do they raise the car when you bolt them up?
Do I need longer (S14 maybe) inner tie rods?
Do I need to move my steering rack forward with these?

GKTECH · 01-04-2018, 03:03 PM

Quote:

Originally Posted by da_crew10

Question Maybe MOTARY can shimmy in: I am looking into the GKTech knuckle adapters that provide 40mm of correction which should be more than enough with my current set up. I just have a few questions if anyone has any experience with these.

Do they raise the car when you bolt them up?
Do I need longer (S14 maybe) inner tie rods?
Do I need to move my steering rack forward with these?

1. No
2. Probably
3. Only if you're running extreme amounts of camber and or caster

jaysgottaredtop · 01-04-2018, 03:07 PM

Do they raise the car when you bolt them up?
No. Wheel, hub, knuckle, coilover, and chassis all effectively remain the same relative to each other.

Do I need longer (S14 maybe) inner tie rods?
Yes, longer tie rods will likely be needed. Exact length will depend on which FLCA you're using.

Do I need to move my steering rack forward with these?
Eh, not exactly needed per se. But you will be more likely to overcenter at a lower steering angle with the standard rack location. If possible, it's not a bad idea to relocate the rack while you're at it.

Edit, Greg beat me to it. When in doubt, trust his words over mine, lol

da_crew10 · 01-06-2018, 02:59 PM

Quote:

Originally Posted by GKTECH

1. No
2. Probably
3. Only if you're running extreme amounts of camber and or caster

Quote:

Originally Posted by jaysgottaredtop

Edit, Greg beat me to it. When in doubt, trust his words over mine, lol

Thank you fellas!

So would the gktech offset rack spacers that move the rack forward be the product I need to buy If I do the knuckle adapter mod ? Same thing as moving the rack forward? Any downside to these? Stress the rack too much maybe? Also any rack boot options out there for these?

*TheRealSy90* · 01-07-2018, 05:17 AM

Quote:

Originally Posted by da_crew10

Thank you fellas!

Ideally you want the crossmember modification to move the rack as far forward as you can.

Sent from my iPhone using Tapatalk

McRussellPants · 01-07-2018, 10:38 AM

Quote:

Originally Posted by Motary

Actual anti-squat, the side view instant center is changed as the knuckle rotates and height from ground changes.

Yeah I guess that knuckle rotation would raise the outboard pivot.

Seems like the last thing the last thing the S chassis would need would be a shorter more dynamic anti squat instant center.

If you actually want less anti squat then lowering the front LCA pivot or raising the rear LCA pivot would be what you were looking for. Most of the benefit of lengthening the traction link would come from a slightly more consistent anti %

jaysgottaredtop · 01-07-2018, 02:50 PM

Quote:

Originally Posted by TheRealSy90

Ideally you want the crossmember modification to move the rack as far forward as you can.

+1. I used the solid PBM relocation bushings, but didn't care for them.

First off, they don't move the rack very far forward. Second, you're clamping smooth metal against smooth metal without crazy tight lateral tolerances, so the rack will actually slide back and forth when hitting lock hard. After hitting lock on a left corner, suddenly your steering wheel centers itself to the right. Then after a right corner, you're centered to the left.

I had the x-member modified to relocate the rack and I switched back to rubber bushings, and the movement went away. In hindsight, I should have just done that from the beginning.

Motary · 01-09-2018, 04:21 PM

Quote:

Originally Posted by Mitsubayati

Can someone please help me find out where I can get a "double adjuster"like the one below? I've been searching for a bit and it seems strange that these aren't so easy to find considering so many suspension components use them for adjusting. I want to upgrade a set of RUCAs I have to better rod ends but they are using a thread type which is hard to find. Ideally I need the double adjuster to have an internal thread of m16x2 and external thread of m20x2.

I think it is this one:

https://www.polyperformance.com/susp...-tube-adapters

Bnr32gtr · 01-09-2018, 06:18 PM

Jay is 100% on the pbm eccentric rack bushing are complete shit. 1 track day completely trashed a brand new remaned rack. I have gk tech now and the tolerance on them seem way better. Rack is not just moving left to right just like jay said. Time will tell. Next time I'm getting fraction motor sports subfame. Just was not in the budget at the time

tuzzio · 01-26-2018, 08:12 AM

Anybody running the Gktech grip knuckles yet?

I was looking at them the other day and I'd love to have the geometry correction they offer. I have no use for angle mods for what I do with my car. I can't imagine there are any downsides to these. Figured I'd ask because I couldn't find any reviews on them.

PoorMans180SX · 01-28-2018, 11:34 AM

Quote:

New improved version from Dec 2017 - All the usual brake calipers should now fit correctly including internal drum handbrake mechanisms!

PoorMans180SX · 01-29-2018, 08:44 AM

Added sway bar options to the end of the steering angle post, with more pics coming later today.

Also, if anyone has the lengths for Z32 and Z33 tie rods, I'd like to add those to the list on post two.

PoorMans180SX · 01-30-2018, 08:09 AM

Wisefab at it again.

https://youtu.be/m8IRrcOTFgY

*TheRealSy90* · 01-30-2018, 08:52 AM

Great now I want that and get rid of my current lock kit that I just finished piecing together...

PoorMans180SX · 01-30-2018, 08:56 AM

Quote:

Originally Posted by TheRealSy90

Great now I want that and get rid of my current lock kit that I just finished piecing together...

Right? I'm furiously adding up the cost of my current planned kit hahaha.

gaz_moose · 01-30-2018, 08:58 AM

do you guys not just cut and shut the OEM subframes to stop the rack going over centre?

RedSled · 01-30-2018, 09:38 PM

got an s13 subframe with spl solid bushings ,what can be done to increase traction ,using the car for drag racing so just need as much traction as possible ,will tilting the subframe be effective ,anyone with actual experience doing so ,and what other mods can i do other than using an s14/15 subframe ,is there a better solution or upgrade i can do to my current suspension

PoorMans180SX · 01-31-2018, 06:46 AM

Quote:

Originally Posted by gaz_moose

do you guys not just cut and shut the OEM subframes to stop the rack going over centre?

Yes, plenty of people do. I still plan on using a 350Z steering rack moved forward on the subframe. I'm also not concerned with being FD legal though.

Quote:

Originally Posted by RedSled

got an s13 subframe with spl solid bushings ,what can be done to increase traction ,using the car for drag racing so just need as much traction as possible ,will tilting the subframe be effective ,anyone with actual experience doing so ,and what other mods can i do other than using an s14/15 subframe ,is there a better solution or upgrade i can do to my current suspension

Z32 guys have been tilting the subframe forever, but there's a high-seven second S13 that runs the stock subframe in the stock position. Probably has to do more with ride height and tires. Are you running slicks, or are we talking DOT tires here? That makes a big difference in launch.

Ruff Ryder 6 · 02-05-2018, 07:21 PM

Quote:

Originally Posted by tuzzio

Anybody running the Gktech grip knuckles yet?

I was looking at them the other day and I'd love to have the geometry correction they offer. I have no use for angle mods for what I do with my car. I can't imagine there are any downsides to these. Figured I'd ask because I couldn't find any reviews on them.

Any answers to this question? I've really only found a couple pictures of them on people's cars. I have the V1 modular knuckle now. My biggest problem is the actual drop on them. With my coilovers (KW clubsport) I have the coilover at the tallest setting and the car is still pretty low. I'd like to actually go back up just a hair. I tried to email GKTech to see about the spindle relation to stock. It says the ball joint height is lowered, and really that's all I want. I need to retain the wheel speed sensors. Any help here?

GKTECH · 02-05-2018, 07:33 PM

Quote:

Originally Posted by Ruff Ryder 6

Any answers to this question? I've really only found a couple pictures of them on people's cars. I have the V1 modular knuckle now. My biggest problem is the actual drop on them. With my coilovers (KW clubsport) I have the coilover at the tallest setting and the car is still pretty low. I'd like to actually go back up just a hair. I tried to email GKTech to see about the spindle relation to stock. It says the ball joint height is lowered, and really that's all I want. I need to retain the wheel speed sensors. Any help here?

Not a great deal of people are running the grip knuckles as yet. They're not as popular as the drift related knuckles.

An easy solution is to run a spacer at the top of the strut.

I'm not quite sure what you mean by you trying to email us?

The grip knuckles are the same as the billet knuckles in the sense that the height has not been increased. Essentially the spindle has been raised but everything else remains.

Ruff Ryder 6 · 02-05-2018, 07:36 PM

If the spindle height is in the same location as stock then I’m in.
I tried using the online form from the website to submit my question.

GKTECH · 02-05-2018, 07:59 PM

Quote:

Originally Posted by Ruff Ryder 6

If the spindle height is in the same location as stock then I’m in.
I tried using the online form from the website to submit my question.

The spindle is raised.

That's odd. We've been receiving other messages via the website fine. Sorry about that.

tuzzio · 02-06-2018, 08:07 AM

I spoke with GKtech via FB messenger around when I posted that, I'll be placing my order likely this week.

PatPs13 · 02-06-2018, 08:48 AM

Quote:

Originally Posted by PoorMans180SX

Yes, plenty of people do. I still plan on using a 350Z steering rack moved forward on the subframe. I'm also not concerned with being FD legal though.

What is the advantage of using the 350z steering rack? Is it wider?

*TheRealSy90* · 02-06-2018, 07:18 PM

I believe it’s actually narrower, and less travel.

Sent from my iPhone using Tapatalk

mr.nismo. · 02-06-2018, 08:11 PM

Quote:

Originally Posted by tuzzio

I spoke with GKtech via FB messenger around when I posted that, I'll be placing my order likely this week.

Placed my order for grip knuckles this morning. Excited to get them

Sent from my SM-G955U using Tapatalk

01-04-2018, 03:07 PM	#7537
jaysgottaredtop Zilvia Addict Join Date: Mar 2011 Location: Greensboro, NC Posts: 950 Trader Rating: (7) Feedback Score: 7 reviews	Do they raise the car when you bolt them up? No. Wheel, hub, knuckle, coilover, and chassis all effectively remain the same relative to each other. Do I need longer (S14 maybe) inner tie rods? Yes, longer tie rods will likely be needed. Exact length will depend on which FLCA you're using. Do I need to move my steering rack forward with these? Eh, not exactly needed per se. But you will be more likely to overcenter at a lower steering angle with the standard rack location. If possible, it's not a bad idea to relocate the rack while you're at it. Edit, Greg beat me to it. When in doubt, trust his words over mine, lol __________________

01-29-2018, 08:44 AM	#7546
PoorMans180SX Zilvia.net Advertiser Join Date: Nov 2005 Location: Michigan Age: 33 Posts: 5,432 Trader Rating: (16) Rides Gallery: PoorMans180SX Feedback Score: 16 reviews	Added sway bar options to the end of the steering angle post, with more pics coming later today. Also, if anyone has the lengths for Z32 and Z33 tie rods, I'd like to add those to the list on post two. __________________ Build: http://zilvia.net/f/showthread.php?t=643065 Friends don't let friends buy knock-offs.

01-30-2018, 08:09 AM	#7547
PoorMans180SX Zilvia.net Advertiser Join Date: Nov 2005 Location: Michigan Age: 33 Posts: 5,432 Trader Rating: (16) Rides Gallery: PoorMans180SX Feedback Score: 16 reviews	Wisefab at it again. https://youtu.be/m8IRrcOTFgY __________________ Build: http://zilvia.net/f/showthread.php?t=643065 Friends don't let friends buy knock-offs.

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

01-09-2018, 06:18 PM	#7543
Bnr32gtr Zilvia Addict Join Date: Feb 2013 Location: Mason-Dixon Age: 34 Posts: 600 Trader Rating: (8) Feedback Score: 8 reviews	Jay is 100% on the pbm eccentric rack bushing are complete shit. 1 track day completely trashed a brand new remaned rack. I have gk tech now and the tolerance on them seem way better. Rack is not just moving left to right just like jay said. Time will tell. Next time I'm getting fraction motor sports subfame. Just was not in the budget at the time

01-26-2018, 08:12 AM	#7544
tuzzio Nissanaholic! Join Date: Oct 2013 Location: Western Mass. Posts: 2,254 Trader Rating: (3) Feedback Score: 3 reviews	Anybody running the Gktech grip knuckles yet? I was looking at them the other day and I'd love to have the geometry correction they offer. I have no use for angle mods for what I do with my car. I can't imagine there are any downsides to these. Figured I'd ask because I couldn't find any reviews on them.

01-30-2018, 08:58 AM	#7550
gaz_moose Zilvia Member Join Date: Mar 2008 Location: engerland Posts: 242 Trader Rating: (0) Feedback Score: 0 reviews	do you guys not just cut and shut the OEM subframes to stop the rack going over centre?

01-30-2018, 09:38 PM	#7551
RedSled Leaky Injector Join Date: Mar 2007 Location: chilling Posts: 106 Trader Rating: (3) Feedback Score: 3 reviews	got an s13 subframe with spl solid bushings ,what can be done to increase traction ,using the car for drag racing so just need as much traction as possible ,will tilting the subframe be effective ,anyone with actual experience doing so ,and what other mods can i do other than using an s14/15 subframe ,is there a better solution or upgrade i can do to my current suspension

02-05-2018, 07:36 PM	#7555
Ruff Ryder 6 Zilvia Junkie Join Date: Sep 2006 Location: TN Posts: 445 Trader Rating: (11) Feedback Score: 11 reviews	If the spindle height is in the same location as stock then I’m in. I tried using the online form from the website to submit my question.

02-06-2018, 08:07 AM	#7557
tuzzio Nissanaholic! Join Date: Oct 2013 Location: Western Mass. Posts: 2,254 Trader Rating: (3) Feedback Score: 3 reviews	I spoke with GKtech via FB messenger around when I posted that, I'll be placing my order likely this week.