does this wear/damage look normal?
i have done 1 track day and about 12 autocross events on these tires over 8 months, including a 4 month break int he winter. its only the driver side front tire that looks like this as i make many more rights than left turns at the events. the passenger side front is not separating and is wearing more evenly. there is only about 3500 miles on these tires, maybe less if i check my records, at least half of those miles are highway driving to the events.
many other drivers at autocross are running street tires and not having this issue with many many more miles and wear on their tires.
these are Cooper Zeon RS3-S tires. supposed to be their highest performance tires. Developed for OEM application for the Roush mustang. "track tested" they claimed.

discount tire is claiming that they are just not meant for the type of use i had them in and that the temps got too high.
while i agree with that in principle i dont see many people having this problem with their 300 treadwear street tires at track days or autocross events.

do you think i have a legitimate argument with cooper tires here?
after my track day a month ago i had about 4-5 of these tears-separation areas on the shoulder tread. then 2 weeks later ran another autocross and maybe had 1-2 more. then after autocross today the entire shoulder is torn and separated.
I have the 2nd day of the autocross tomorrow and a track day on monday so i had to get some replacement fronts of whatever the local place had in stock. Falken 612 model is what they put on the front to cover me for a couple weeks until i upgrade to a better set all around.

tire pressure i run during autocross is about 40psi. which is the pressure i have found works best to keep the tire from rolling over the sidewall, and wearing at the markers on the shoulders as it should. i check my tire pressure very often to make sure it doesnt get too high or too low and always return the tires to everyday driving pressures after the events.
the damage started on the shoulder like that after the 1 track day i did. i ran six twenty minute sessions, which was about 8 laps per session, 7 hot laps and 1 cool down lap. about 45 minute break between each session.
i was running around 38-40psi that day at the track in the fronts. so by the end of the day it was about 50 laps, and each lap had about 7 right hand turns and only about 1 left.
initially there was about 4-5 of these gouges in various spots around the tire. then next autocross it stayed the same, then this last autocross the whole tire went to hell. today was pretty high heat to, probably 90 degrees on the driving surface.
in high speed turns or even low speed hard turns the car really leans on the outside edge of the tire. i plan to get a camber kit but i was just really surprised on how quickly this tire got destroyed.
which is why i feel like its more a failure on the tire vs something not right on the car.
Id just buy another tyre and recheck the alignment, it's not worth the never ending arguement over road damage, tyre pressure, kerb damage, etc etc.
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im more disapointed with cooper, as many other drivers are using street tires and getting better wear/durability than this.
I replaced the fronts with Falken 612's since that was one of my few options in the time crunch that i was in. After running the 2nd day of the autocross on them i can tell the falkens have better sidewall rigidity than the coopers did.
im doing a track day tomorrow, i will try to somewhat take it easy so that i dont destroy these fronts as well but it will be a good gauge on if they are more durable than the cooper zeon's.
I will look into the camber specs and adjustments this week. from what i researched on here already im understanding that our cars only have very minimal camber adjustment capabilities? is this true?
We can get eccentric bolts to get slightly more adjustability? but need the KMAC setup to get full adjustability?
what sway bard do you know of people using? from what i have read there isnt really any aftermarket bars that are improvements over stock, id be happy to hear that there is!
also, the all season 'run of the mill' falken tires i can already tell are stiffer in the sidewall and holding up better than the coopers did. might have to do with load rating of the tires which i hadnt really looked at in the past.
I would have completely agreed with the guys at the tire shops had i not seen people go harder on tires that are supposedly "lesser performance" than mine and not have failure like i had. but again they did bring up the load rating at the shop, that may be the key for a car like ours that leans so much on the relatively skinny front tires.
Kmac bushes change the amount you can move the lower control arm from 3mm +/- to 6mm +/- which is about .75 of a degree in real terms. More neg camber wont hurt but it wont solve that issue.
Kmac bushes change the amount you can move the lower control arm from 3mm +/- to 6mm +/- which is about .75 of a degree in real terms. More neg camber wont hurt but it wont solve that issue.
i agree.
to me the camber is just to get the car to handle better since this front left tire takes so much of the load in the right hand turns. this tire failed prematurely under load and heat in my opinion. a better tire would not have.
with that said, the car still needs a bit more negative camber to handle better and let more of the tire patch be in contact with the ground under hard cornering vs rolling to the outer edge as it is now. when i have better tires they will still wear prematurely on the outer edge due to the amount of lean/roll and abundance of right hand turns, hopefully less with more neg camber.
Front left:
camber: -0.8 (spec range -0.8/-0.2)
caster: 4.5
Toe: 0.24 (spec Range 0.12/0.29)
SAI: 12.2
Included angle: 11.5
Front Right:
camber: -0.8
caster: 4.3
Toe :0.22
SAI: 18.7
Included angle: 18.0
do you guys know how far negative we can go on camber on the stock mounting bolts?
how far you can get with the bolts depends where you're starting from. i can tell you the adjustment bolts generally get you another .3 degrees one way or the other depending on which way they are installed, compared to the stock bolts in middle location.
your front toe could also be closer to zero, but it's not responsible for that wear..
i do alignments at my dealer. i'd recommend talking to the guy doing your alignment, he'll understand what you're going after and work with you.
Last edited by benzslo; Jul 9, 2013 at 09:24 PM.
how far you can get with the bolts depends where you're starting from. i can tell you the adjustment bolts generally get you another .3 degrees one way or the other depending on which way they are installed, compared to the stock bolts in middle location.
your front toe could also be closer to zero, but it's not responsible for that wear..
i do alignments at my dealer. i'd recommend talking to the guy doing your alignment, he'll understand what you're going after and work with you.
i posted the photo on their FB page, and they did respond asking for my contact info, but i have not been contacted by them as of yet.
I will talk with the guys at the shop and see what we can do with adjustment bolts on the camber. anything additional i can get in the front will help, i will try that first before investing in the KMAC.











