Paul902

My car is 25% track / 75% street. I am just under RS height (118mm left, 123mm right after corner balancing, vs 124mm for RS), have -1.5 degree front camber and and touch of toe out, with stock uprights. I am seeing more front inner tire wear than I'd like. Can part of this tire wear be attributed to bump steer, and would evo uprights correct that, or is it just down to the camber? I'm trying to weigh cost/benefit of evo uprights vs pinning the stock tie rods. Please advise.

trophy

Bump steer is not going to attribute to any additional tire wear, any toe settings is going to be the culprit. With any amount of toe you are essentially pushing the tire across the road partially sideways scrubbing off rubber as it goes.

It has nothing to do with EVO uprights, however if you need justification for buying them, just tell the wife that reducing bumpsteer will make the car much safer

Matt Lane

Hi Paul,

Did you have your alignment done by Andrew at WeTune? Can you please drop me an email at matt_lane AT silanis.com? Would like your feedback.

Best,

Matt

Bill Verburg

I agree, it has nothing to do w/ the uprights, you have too much camber and + toe for your use, if the car was tracked a lot you'd wear the outer edges of the tire from too little camber.

street specs are

Front height 154+/-10
rear height 147+/-10
max l/r diff 5mm
Toe(front)mm +5+/-5'
Toe(rear)mm +10'+/-5'
camber(front) -20'+/-10
camber(rear) -1*10'+/-15'
caster 5*20'+15'-30'
and for RS

124+/-10
107+/-10

+5+/-5'
+10' +/-5'
-1* +/-10'
-1* 20' +/-10'
5*20'+15'-30'

the difference is that when the car is lowered to RS you will want the RS uprights

for pure track use you't go way more aggressive on the alignment, for dual use it's a compromise and you will just have to decide on how much extra wear you can live w/

jscott82

or just leave everything the way it is and do more track days to even out the wear..... :-)

[opinion]At RS ride height, bump steer is borderline dangerous. Unless you have some other mitigating factor (cost, race class, etc) I would get the uprights…. Otherwise I would either raise the car or get way stiff springs to stop the motion...[/opinion]

fast_freddy

I agree. The change to the RS uprights transformed my car. It is so much more benign on the road it isn't funny. Hands down the best money I have spent for mods.

Paul902

Thanks everyone for the insightful comments. I understand bumpsteer is caused by induced toe, so I thought this might be the cause of my excessive inside wear. Sounds like whether or not I spring for RS uprights I need to ease off the camber a bit from last summer's alignment.

Matt - yes, I used WeTune. Good experience. I'll email you.

Bill Verburg

the camber you use depends on you use and tolerance for buying new tires.

If the car is lowered to RS or lower that is when you use the RS uprights and solid rear sides.