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.

so the best thing to do is to buy aftermarket lca's like ikeya formula?

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.

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.

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.

fuck this is compricated.


what about this:

http://www.nengun.com/ikeya-formula/...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.

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!

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

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.

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.

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/uploadIma...DSC04985x8.jpg

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

vs

S15:

http://www.dragsport.com/issue/2008/...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/...0707/s15-5.jpg

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

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.

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...

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?

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).

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.

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

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/c2...711/JICS15.jpg

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

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.

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)?

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).

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 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

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.

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.

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