Unusual tire wear

#1

ok so i have some unusual tire wear occurring, my front right tire is corded on the outside edge, the front left is having the same issue but no corded yet, and the rears are fine. whats even more strange is that the fronts have a ton of tread on the inside of the tire. you might suggest running more camber, however when i take tire temps it suggests that i have too much camber. the inside and middle temps are the same and are about 5-10 degrees warmer than the outside. i need some help on what might be going on here as i dont have money in the budget for unplanned tire purchases!

#2

From what I understand taking tire temps is more complicated than trying to get even temps across the tire. For example what the tire did in the last 30secs impacts tire temps a helova lot more than what it did 60secs ago. So if if the last 30secs were on a straight you’d see increased inside edge temps and decreased outside edge temps, even on a tire with insufficient camber.

The worn outer edge means not enough camber and/or too much body roll. The wear pattern is pretty conclusive, I’d go with what it’s telling you.

#3

What is your hot tire pressure? If your pressure is too low, your tire may be rolling over in corners and really working over that outer tire edge. It also helps to rotate your tires every few runs. On most tracks that I’m familar with, the RR tire get’s the least amount of wear. I give each of my tires a “break run” and cycle them through the right rear.

#4

Remember that tire temps are only a reference to be compared against other tire temps your have taken in the past. Tire temps should be correlated with good laps times to discover the otpimal tire temps for your suspension setup. Since our car cars are so softly sprung, heavy, inadequate sway bars, and run on tall narrow tires, outside tire wear is inevitable due to the camber limitations.

#5

Agreed, too low hot PSI for RA1’s will cause that type of wear assuming your camber is set correctly.

#6

i realized i made a typo in the original post, the outside is cooler not warmer, if that changes anyones diagnosis. also i am still fighting to get my hot temps where i like them. i share the car with my dad who has been runing in HPDE 4 to get his license and so i would always come off the track with hot temps that were usually above 40psi which for my is really not where i like them. and we would drop them down to 38-39 hot for my dad as he would usually go out right as i came in. i have no idea what my camber reading is at the moment but i am running Kmacs in the front (came with the car, not my first choice) running at max camber and nothing adjustable in the rear. i still have yet to redo the rear subframe with adjustable trailing arm mounts.

#7

Cold temps on the outer edge could be explained by 30secs of straight. With a couple degrees of camber, the outer edge doesn’t hardly contact the track’s surface at all on straightaways.

My suggestion would be to ask enough questions such that you get a feel for what most other folks are doing. Use that as a baseline. Then as you gain expertise in the various black arts, expertise that I certainly don’t have, you can nibble around the edges of the baseline with your own unique testing and solutions.

Once you’ve worked hard to find some unique solution that really works well, you can come back to us and lie your ass off. Think how much fun that will be.

#8

In order to get good pyrometer data on the affects of your camber, you might try doing it on a skid pad. That will give you a lot more control over the variables.

#9

I’ve found that tire temps can drop dramatically just after track out. Even in the time it takes to get into pit lane and take temps. If you can find any way to get data aquisition for mid corner temps it would greatly help to figure this out.

Excessive toe out could cause this as well if you are seeing hotter inside temps.