tire wear issue / question.

[Evo442]

Ok, I took off my track tires and noticed that the inside of the left front tire is worn down below the wear bars. the other side of the tire is fine, tread well above the wear bars, as is the tread on the 3 other tires.

My track tires are 255/40/17 ra-1's and were full tread depth when I got them. this was my 2nd day on these tires, both at Thill in the CCW direction.

I'm running -2.5 deg neg camber in front with 1/16 toe out.

I'm thinking that at Thill, in a majority of the turns, the left side of the suspension is unloaded. particularly with the negative camber and no front lsd, the inside part of my left front tire is getting ground down as spins its way through the left hand turns.

does that explanation for this tread wear make sense or should I have my alignment checked? My street tires show no uneven wear.

[earlyapex]

my 255/40/17 RA1's did the same thing at thill on monday, Drivers side front inside worn way more than the rest.

I just got an alignment the day before so I know its not that.

What hot pressures where you using?

I think your right on your theory. I had the same one. :) I have front LSD though, I don't think its from the tire spinning but from me sliding everywhere.

-2.7 front camber , -1.4 rear, zero toe

[Evo442]

my 255/40/17 RA1's did the same thing at thill on monday, Drivers side front inside worn way more than the rest.

I just got an alignment the day before so I know its not that.

What hot pressures where you using?

I think your right on your theory. I had the same one. :) I have front LSD though, I don't think its from the tire spinning but from me sliding everywhere.

-2.7 front camber , -1.4 rear, zero toe

Fooled around with the pressures in the am. Left things alone for the last session of the am and the pm. Here were my last 3 sets of pressures coming off the track after a cooldown lap.
In order: LF, RF, LR, RR:

40,40,37,37
41,41,37.5,37.5
42,43,38,38

What pressures were you running, hot? I wonder what pressure my right front tire was at on the track if it was 43 after a cooldown lap in my last session...

[earlyapex]

Yea 43 hot is way too much.

I was told to keep them in the mid to high 30's hot.

Beginning of the day I was at 44hot
:shock:

Dropped them down to around 38 hot and they gripped and communicated much better.

[Evo442]

Yeah, I'll have to start lower next time. My car did have more understeer than it should have by the end of the day.

[vtluu]

I run my Kumho Victoracer 275/40-17s at 32-33 psi hot (all corners). Wear has been pretty even on all of them--the nice thing about them is they're not directional so I can put any wheel on any corner--definitely helps even out wear. They've had 3 track days (and 1 autocross), and look like they're good for about 2 more.

[Evo442]

the ra-1's are really only directional for the rain. you can swap ra-1's any which way as long as its dry...