Help me read my tire wear

[andyk5]

4th track day (2 SOW 2 BW CW13) on 225/45/17 Cup2s drivers side front rotated after every track day. Car is stock except top hats, camber bolts and alignment. I don't remember what the camber on the front is but I think it is under 2 degrees.

Usually all my 200-240tw tires wear this way. First I wear out the center strip, than the outside half of the tire with the inside basically brand new.


So what are the issues here?

1) Not enough camber? If so can I get more by adding a second set of camber bolts (upper hole, opposite side) or gotta have coil overs now?

2) Am I losing the center strip first due to over inflation?

3) I drive pretty aggressively, maybe I am causing too much understeer due to steering angle?

[Racecomp Engineering]

1. yes more camber needed.
2. possibly. what pressures are you running?
3. hard to say from here! are you fighting understeer a lot?

also are you on stock wheels?

a tire pyrometer might help you a lot.

- Andrew

[Ohio Enthusiast]

Originally Posted by andyk5

If so can I get more by adding a second set of camber bolts (upper hole, opposite side) or gotta have coil overs now?

I'm on RCE Yellow springs, camber bolts in both top and bottom and Pedder's offset top hats and have -3 camber and could gain a little bit more (between -3.2 and -3.4, I dialed it back a little for the street).

Originally Posted by andyk5

First I wear out the center strip

What's your tire pressure? Sounds like you're running too high pressure?

[andyk5]

Originally Posted by Racecomp Engineering

1. yes more camber needed.
2. possibly. what pressures are you running?
3. hard to say from here! are you fighting understeer a lot?

also are you on stock wheels?

a tire pyrometer might help you a lot.

- Andrew

Pressures vary from 28-30 cold, to 33-37 hot.

I don't fight understeer a lot, I actually fight oversteer most of the corner. I guess corner entry I div in pretty hard and the car pushes but mid corner and corner exit is always a battle against oversteer.

I am on stock wheels. Tire pyrometer seems like too much over head. I need to do hot laps then come to hot pits get out, check tire temps and record right?

[Code Monkey]

Originally Posted by andyk5

Tire pyrometer seems like too much over head.

There's your problem.

[Racecomp Engineering]

Originally Posted by andyk5

Pressures vary from 28-30 cold, to 33-37 hot.

I don't fight understeer a lot, I actually fight oversteer most of the corner. I guess corner entry I div in pretty hard and the car pushes but mid corner and corner exit is always a battle against oversteer.

I am on stock wheels. Tire pyrometer seems like too much over head. I need to do hot laps then come to hot pits get out, check tire temps and record right?

It's not conceptually difficult to use, but it can be a pain to do by yourself.

Either way, yes I think more camber would help. How do your rear tires look? More front roll resistance could also help.

- Andrew

[strat61caster]

Looks over driven with too much steering input more than anything else. I bet decreasing pressures helps the first time you try it and then you get comfy pound on them again and the problem persists. More camber will be better but won’t solve what you’re seeing here.

Are those GT radial sx2 or Michelin?

Edit: either way back down the speeds in corners, tires shouldn’t be screaming, ideally they whisper. You can make them scream for a lap but after that you get the wear you see above.

[andyk5]

Originally Posted by strat61caster

Looks over driven with too much steering input more than anything else. I bet decreasing pressures helps the first time you try it and then you get comfy pound on them again and the problem persists. More camber will be better but won’t solve what you’re seeing here.

Are those GT radial sx2 or Michelin?

Edit: either way back down the speeds in corners, tires shouldn’t be screaming, ideally they whisper. You can make them scream for a lap but after that you get the wear you see above.

They are Michelin Cup2s but my RT660s wear the same exact way. The only tire that can take my abuse and not get destroyed like this are GT radial SX2s and thats mainly due to them turning in to a hockey puck and just slide after the 3rd track day.


Edit: I think I don't know how to drive fast without abusing my fronts... my laptimes are not even that competitive, running 2:10 at buttowillow with this setup, should be 2:06 ish to be considered reasonably fast.

[andyk5]

Originally Posted by Racecomp Engineering

It's not conceptually difficult to use, but it can be a pain to do by yourself.

Either way, yes I think more camber would help. How do your rear tires look? More front roll resistance could also help.

- Andrew

[Muskoka800]

Originally Posted by andyk5

Tire pyrometer seems like too much over head.

The cost of a pyrometer is half that of one new tire. So, before ruining another set…
I bought mine on eBay.

[andyk5]

Originally Posted by Muskoka800

The cost of a pyrometer is half that of one new tire. So, before ruining another set…
I bought mine on eBay.

Ok, if I a have a pyrometer and have some measurements lets say mid session, what do I do with that information?

[Code Monkey]

It tells you if you are camber limited, if the tire is overinflated, etc.

Get the deluxe version.

[soundman98]

Originally Posted by Code Monkey

It tells you if you are camber limited, if the tire is overinflated, etc.

Get the deluxe version.

false. a pyro meter doesn't shout "camber!" or "overinflated!", the same as a hammer doesn't build a house.

a hammer is used to nail wood together that can build a house, just as a pyrometer can be used to tell temperature across the width of the tread.

it's how the tool is used, and the information it provides is used that determines the tools functionality.

how does a fancy temperature probe tell camber or pressure issues over a bad wheel bearing or terrible driving?


i'm not saying that it's not part of the solution, but it's not THE solution. even worse, is if the OP were to get one, and then it sits on the shelf.

[andyk5]

Originally Posted by soundman98

false. a pyro meter doesn't shout "camber!" or "overinflated!"

If it did I'd def buy one lol.