First HPDE-Tire Wear Questions
 

I completed my first HPDE over the weekend and have some questions regarding the tire wear. I kept the air pressure at 35 cold all the way around but the front left was still wearing heavily on the shoulder. I didn't take hot pressures or temps. Car is stock, minus tires (RE-71R) and brakes.

What would you recommend for next session? More/less air, camber bolts, etc?

Thanks for any advice.

congrats on completing your first HDPE! Additional negative camber using camber bolts up front would help dramatically.

These cars eat up the shoulders. Camber limited up front. I hear the RE71Rs are very soft, so don't expect them to live long. Long fast sweepers really kill these tires.

I would bump up air pressures to keep the sidewall stiffer and see if it helps. Though 35 cold means 40~ hot, so that should be pretty stiff. Get camber bolts, but that'll only get you -1 to -1.2ish. If you want to go more hardcore, then a suspension with camber plates. A front sway bar might help spread the load a bit so it isn't all on one wheel/tire, but benefit would be pretty minor there. Not sure if I have a mechanical recommendation other than these.

To manage wear, rotate the worn shoulders to the rear.

How do you like them by the way? What size tires are they? 225s? 245s?

They are stock size, 215s. I like them a lot. Grip felt the same even as I was getting faster in the afternoon here in AZ.

Would you recommend getting a suspension so soon? I got good feedback from the instructor and moved to group 2 early. I have heard to keep mostly stock to learn to drive better and upgrade later, but looking for any advice.

You can make upgrades to adjust camber without really "upgrading" anything. Rear lower control arms and a camber plate and camber bolt up front will allow full adjustability but will not change the stock suspension of the car at all (assuming you buy rear LCAs that don't lower the car). The stock suspension with proper camber is very capable and will serve you well until you have more experience under your belt.

Get a good tire pressure gauge. Get front camber bolts. Get an alignment. Usually run groups are based on the ability to coexist peacefully on the track. Situational awareness when a Viper can sneak up at the end of a straight, going 50mph faster than you.

Camber bolts from Toyota are super cheap and easy to install, so I would do them for sure.

Otherwise, I'd learn to drive the car within its capabilities, which in the case of your heavy front tire wear means you probably need to enter the corners faster, maintain your throttle a bit longer before getting on it. IMO, the car is understeering because you're getting on the throttle a bit too soon; the steering wheel needs to be unwound just a bit more first. The understeering is eating your front tires.

Also, I would not go any higher than 35PSI cold. Check them when hot; I would not want to see much more than 38PSI hot.

how long were your sessions?


heat, poor alignment, and overdriving are the top reasons for excessive tire wear, all 3 are controllable.

Sessions were 20 minutes each, 8 total.

You don't need any more camber on the rear. I use 2x bolts up front for -2.5 with good results.

You need more camber :)

OEM camber bolts in front will sort out most of your problem very cost-effectively.

Also, some tracks are just harder on one side than the other. The directional pattern doesn't matter in dry conditions, so feel free to rotate them side to side between sessions.

IIRC, tire pressure should be somewhere around 38psi hot (you can gain 5psi or more when pushing the car), and camber no less than -2.5 all around, preferably -3 or little more up front. This is for track and I drive with this alignment on the street late Mar - early Nov...then switch to winter tires and -1.5 all around. You will need camber plates and LCA to get these numbers unless you're dropped low in the rear. Front gains positive camber on compression (wheels straighten out) and rear gains negative on compression.