[mcbat8]

Originally Posted by WhiteMale

Toe is out of spec? Have you rechecked it?

I had the car aligned for 0 toe before the track day. Will recheck soon

[wakespeak]

Too much camber. Try -2.8 to -3.0 (factory track spec for the ZL1 1LE is -2.7). I get too much inner tire wear over -3.0. I also think more understeer due to tire patch being reduced except in tight corners with a lot of trail braking (just like you are seeing). Too much camber also reduces your braking.

Also be sure to wait for a warm up lap or two before going 10/10s for tire wear.

[mcbat8]

Originally Posted by wakespeak

Too much camber. Try -2.8 to -3.0 (factory track spec for the ZL1 1LE is -2.7). I get too much inner tire wear over -3.0. I also think more understeer due to tire patch being reduced except in tight corners with a lot of trail braking (just like you are seeing). Too much camber also reduces your braking.

Also be sure to wait for a warm up lap or two before going 10/10s for tire wear.

yeah, I am going to try -3.0 next. I took a razor blade to the left outside shoulder and there is only about 1.5mm of rubber left as well so I think -3.0 should work well for me.

[N Camarolina]

Originally Posted by mcbat8

yeah, I am going to try -3.0 next. I took a razor blade to the left outside shoulder and there is only about 1.5mm of rubber left as well so I think -3.0 should work well for me.

Based on the photo you posted of your tires, where it looks like you are wearing the shoulders more than center, I'd also suspect that you running your sessions on under-inflated tires. One of my instructors has an SS 1LE and would start his sessions at 26 or 27 PSI, eventually working up to 35 or so by the end of a 25 minute session; he had a similar wear pattern to yours. We both talked to the guy that rents Camaros at VIR and he suggested starting around 29-30 psi to ensure target PSI is reached by the middle of a session so the tire walls don't get rolled over and caused excessive wear.

Regarding your observed understeer problem, I'll add on to the other great observations and suggestions other posters have made: If you correct your contact patch problems (less camber, appropriate psi) and trail brake further into the corner and still find that you are understeering in corners, it could simply be because you are entering the corner with a bit too much speed. In that scenario, the combined lateral (turning) and longitudonal (trail breaking) G force may be exceeding front tire grip limits, which can only yield understeer.

[mcbat8]

Originally Posted by N Camarolina

Based on the photo you posted of your tires, where it looks like you are wearing the shoulders more than center, I'd also suspect that you running your sessions on under-inflated tires. One of my instructors has an SS 1LE and would start his sessions at 26 or 27 PSI, eventually working up to 35 or so by the end of a 25 minute session; he had a similar wear pattern to yours. We both talked to the guy that rents Camaros at VIR and he suggested starting around 29-30 psi to ensure target PSI is reached by the middle of a session so the tire walls don't get rolled over and caused excessive wear.

Regarding your observed understeer problem, I'll add on to the other great observations and suggestions other posters have made: If you correct your contact patch problems (less camber, appropriate psi) and trail brake further into the corner and still find that you are understeering in corners, it could simply be because you are entering the corner with a bit too much speed. In that scenario, the combined lateral (turning) and longitudonal (trail breaking) G force may be exceeding front tire grip limits, which can only yield understeer.

Thanks for the feedback on tire pressure. I did start around 27-28 psi and came to similar conclusion that it's probably too low since I start pushing before optimal psi of 33. I'll try 29-30psi to start.

[Christian1LE]

I start my tires around 23-24 PSI for time trial and I have -2.3 camber, i have no issues with tire wear that you're seeing. Obviously my camber is not as high as yours though. If you want better tire wear you should probably shoot for 36 PSI hot, for laptimes you probably want 30 or lower. Id suggest getting a pyrometer next time you're on track and seeing what temperatures you're getting between the inside/middle/outside of your tires. That should help you guide your camber selection.

[Val Walkinshaw]

Can confirm the sweet spot is 35/36 with FE4 suspension assuming also SC3R tires.
I start my track day at 29 and at the most 30 and at the end of the first session i'm at the sweet spot.
My track instructor says that if mid corner you are struggling with understeer then you need more toe. Negative toe in the rear is this cars best friend on track. Positive toe makes the ass end kick out in simple terms.

I ran .05 which is a hair under 4/64.
.12 is 1/8 on both sides which is a total toe of 1/4. That would be considered aggressive and you wouldn't want to go anymore than that. I personally have ran both 1/8 and 1/4 and preferred 1/8 in toe on each side. Again,negative toe.

Many Auto crossers I have been friends with prefer positive toe in the rear with a square setup but for Camaros and track negative is what you want.