Raptord

iTrader: (10)

Hey guys,

My RS3's have worn a bit odly to me it seems as I do track days. Many of you have more experience than me, so I was hoping some of you could take a look at how my tires are wearing and help me figure out what's going on.

The tires are 255/40R17's on stock BBS'.

Front alignment: -3 camber, 0 toe for track // -1.2 camber, 0 toe for street (I switch between them when I get to/leave the track)
Rear alignment: -1.3 camber, 0 toe

I'm particularly interested in what's going on with the inside tread of the rear tire, and the little "holes" on the inside tread of the front tire. The pictures don't show it much, but there are similar holes on the outside as well.

Tire wear pictures: https://goo.gl/photos/7B37BP1dEng4vkVr6

Any insight would be appreciated. Thanks!

MinusPrevious

iTrader: (3)

Not claiming the expert title, but I do some tire wear analysis in the work I do

Wont comment on the edge wear but the blisters / chunking are likely due to overheating the tire
Tire Rack has a good explanation here:
http://www.tirerack.com/tires/tirete...jsp?techid=67&

EVO8LTW

iTrader: (41)

Also no expert, but it does look like the tires are overheating with the chunking. Factors in play may be too low of pressures, overdriving the car and pushing through turns, extremely hot weather and track temp, or maybe an alignment issue. You mentioned two different camber settings up front for street and track. Are you re-adjusting the toe when you adjust the camber? You may have a toe issue that is scrubbing the front tires' edges. The toe changes significantly when you move the camber setting.

EDIT: Toe changes significantly when you adjust camber from a camber plate. Not sure how the factory camber bolt affects toe.

Raptord

iTrader: (10)

Yes, I'm re-adjusting the toe when I make camber changes. When I get my alignments done I have them align the front at both settings I want so that they can tell me how many turns on the tie-rods are needed to switch between the settings.

I've always targeted ~35 psi hot, and had always been confident that was roughly the right temperatures, but looking at the sidewall roll-over and the tires looking like they were overheating. I never knew lower pressures increased tire temps until some reading I did following Minus' comment. May be time for me to finally get a tire pyrometer.

MrAWD

Another no expert here as well!

Looks like your rear tires are riding outside edges much more than inside ones, and from running 1.3 degree of camber, I would say you need a bit more there.

Fronts have way more wear on the inside edge and that is where you see effect of that extra heat. You are either having too much toe or too much camber (or even both) to get that kind of wear. Outside edges don't seem to be abused much at all, which points that you are perhaps running a bit too much camber for your setup/driving style.

ReaperX

iTrader: (5)

I am assuming that this is for a hpde style track day rather than a TA/TT event so my answer will reflect that assumption.

From what I can see in the pictures the tires have been overheated and that is when the abuse occurred. For a 20 minutes track session you have certainly managed to push the tires beyond their limit. That is what the chunking up on the inside is from. It would suggest that once the tires had started to get greasy that they're being pushed even harder.

For your case I would raise cold pressures by 2psi all around and/or do a cool down lap halfway through your session.

Also, yes lower pressure will increase tire temps and vice versa. Reason being is the tire is more flexible and moves around more, generating more heat. Higher pressures don't allow the tire toflex as much which lowers the temp.

Butt Dyno

iTrader: (10)

This is a 255 on an 8" wheel, right? Could that pinching be playing a role?

Raptord

iTrader: (10)

Both HPDE and TA. The TA's I do are 20-min practice sessions in the morning and 10-min timed sessions in the afternoon.

I've long suspected that could be an issue as well. I'll be on 18x9.5's with 245's next year so that will no longer be an issue.