Odd tire wear

Our team switched to NT05's (205/50/15) for our last lemons race on our 280Z. We ran the tires at 35-36 psi hot but have noticed the centers of the tread have an odd wear pattern. It's worn at an angle on the center block down beyond the wear bars. Side blocks have plenty of tread and the tires were not rolling over. Front and rear are both worn this way. Our first thought was that maybe we were running too much pressure. Last weekend we had an autocross and kept dropping pressure to see if anything changed. We got down to 29 hot and the tires started to wear more on the edge but the centers are still wearing the same. Didn't feel too much change in performance. Maybe slightly faster with the drop in pressure?

What are your thoughts?

How wide are the wheels they're mounted on?

They are mounted on 7.5" wide wheels.

Too-narrow wheels for the tires might be causing fast center wear.

Have you checked the alignment recently? I suspect excess toe-out might be causing that.

Certainly looks like over inflation to me. If they are not fat tires squished onto small rims (as asked above, 7.5 with 205's should be fine though)

It also looks like the inside is wearing more (middle pic, is the inside to the right?), so maybe too much camber (lower pressure should help that a bit though) or toe .

Interested, my tires also look like this. 245/45/17 Toyo P1 Sports on 8" wheels. Mostly on the front of a full weight fox mustang. Running around 40psi front helped running 38psi at a different track brought it back.

Our light weight 4 cylinder mustang also did this with 28 lbs pressure bumping it up cured that one.

Both cars have the same size tire and wheel. I believe going to 9" wide wheels or narrower tires will help with the carcass flex.

Reminds me of the Groove Of Doom that old BFG R-compounds would get.

IIRC that was down to tire construction.

We set toe to 1/16" in up front and check it often. Rear can't be adjusted but I think its around 1/8" toed in. Front camber is -2.5 left and -2 right. We squished the right if the car and that's the best we can get for now. Rear is about -1.5 on both sides. Widest recommenced wheel for the NT05 from Nitto's website is 7.5" and the tires look square to maybe little stretched on that wheel.

Not really sure what I should do and I don't know if I can even run these at the next race since they are so worn.

Interested as well... my Bridgestone RE-71R (255/40/17 on 9" rims) shows similar wear in the center running 32-34 psi hot on my MZ3 Roadster.

My rivals (s) look just like that on the spyder. I'd love to hear what's causing it.

The RE71R's on my Cadillac wear like that when I autocross. Not on track, but I'm pretty conservative on track, and not at all street driven. My assumption has always been that this is just how these tires wear when being driven sideways, which is more or less how I autocross. Happens front and rear for me too.

Tire pyromter for those that don't know what's causing it.

Overinflation is it. Toe wears out the inside....

Get a pyrometer...

Do both front tires look the same, or are they mirror images? Did you heat cycle them? Thompson is pretty easy on tires, the next race at NHMS is not so easy, especially to the right front.

In reply to Sonic:

Both left and right side tires are mirror images of each other. We didn't rotate the tires at the last race since the rears had the same wear pattern as the fronts and didn't look any better. Tires were not heat cycled. Having a pyrometer would be nice. Might look into getting one for the next race.

It seems to me like a combo of the really hot temps at that race, along with full tread depth not heat cycled tires, combined with a bit of overdriving with higher slip angles. The hot rubber bends over when cornering and the tread does not present a square surface to the road. This combined with a bit of over driving using higher slip angles than ideal, results in this, like a pencil eraser dragged sideways. Try heat cycling the next set you get and find out who on the team over drives the car, every team has somebody, I know we do.

You can try flipping them on the rim to get more life out of them.