I do some auto-x's, drift events, and pretty aggressive driving on backroads. I noticed my tires are scrubbed like crazy on the outside edges of the tire. The inside edges of the tire are not scrubbed at all. My suspension modifications so far are D-Specs, Stillen F&R adjustable swaybars, and J&M rear LCAs. I believe I need some more negative camber in order to keep the sides of the tires from scrubbing so much during hard cornering. If I buy caster/camber plates, will this solve most of my problem? The scrubbing is a little worse in the front, but it is also present on the rear tires. The sway bars are set to full stiff in the rear and one hole from stiff in the front. Should lowering springs be added instead to increase roll stiffness? I can try to get some pictures of my tires if that will help.

 

More negative camber will help the front out, at some expense with respect to braking grip if you have to push it too far. What are your current camber readings?

"Lowering springs" are something of a mixed bag as far as camber under operating conditions is concerned. You do gain some roll stiffness, given that the springs are at least slightly stiffer than OE. But you give away a little because the average of the front and rear roll center heights drops a little faster than the car does, and you give away a little more because lowering puts you where you get less favorable camber gain. It is possible to come out ahead, overall, if the spring is more than enough stiffer to make up for the other effects.

Some of that tire wear is not suspension related. In those competitive events, you're getting significant lateral tire distortion, as well as vertical deflection. When your car rolls, part of what you see as visible body roll is actually the outside tires "squashing" a bit and the inside tires unloading and their profiles "un-squashing". This is not a small "theoretical" thing - it amounts to about 1° of apparent roll per lateral g.

Have you ever had your REAR cambers measured? I'll bet that they aren't precisely zero (and I hope that they're a small fraction of a degree negative rather than anything positive).


Norm

 

I am sure we can point you in the right direction for your track set up. Bo0th for grip and drift! Since we are the pros...... shoot me an email and we can try to set you up with the right parts for your specific needs.

EricC@STILLEN.com

 

Here are the alignment specs from the last time I went to the stealership:

Front left camber: -0.7*
Front right camber: -0.8*
Rear left camber: -0.1*
Rear right camber: 0.0*

Should I just run higher tire pressures in order to keep the tires from rolling so much? I usually run 32-35 psi, but maybe I should go to 38-40?

 

tire pressure will take a little experimenting to get right for your setup and driving style. but low 30's is probably a good starting point for road racing since you'll be on the track long enough for the temps to rise and the pressures to go up. on an auto-x course you won't be out there long enough to really raise the temps and effect the pressures so you'll want to start higher like the 38-40 mark you mentioned.

ultimately the best way to set pressures is to get a good contact style tire temp probe, they're not that much for basic ones. then you can set a starting pressure, make your auto-x run or road course run, then check and see what your outside, center, and inside temps are. that'll let you know if you're running too much or too little camber, too much or too little tire pressure, everything