Is This Blistering or Is The Tire Bad?

[North Coast Cab]

Checking the tires for tomorrows DE at Mid Ohio and discovered this on one tire. The was a blister type area where one layer of rubber had peeled away. I pulled back and cut it clean. There is still good tread under there, but not sure if they are done or driveable or defective.

John

[MY83SC]

I am no expert. But I'd suspect that, especially at the track, you would quickly lose an entire layer of rubber. It will only get larger. It's as if temps rised beyond what the tire could handle and started to seprate the layers of rubber.
I am sure that the Pro's will chime in soon and let you know if it is due to a defect or normal and if the tire is still safe to track. I know that I wouldn't drive it on the street.

[MY83SC]

Forgot to mention. It appears you have a "Hefty amount of negetive camber there." Looks like you have expieriance a ton of "G" force. :>)...What tire pressure are you running at?

[North Coast Cab]

I ran the tires for 2 days at Beaver Run where there is very new pavement and known for being difficult on tires. I moved the pressures all over from 26/28 to 31/33 cold. I agree with your assesment of the peel factor, but was hoping an expert would chime in and say
Kuhmo would be sending me a new set.

John

[MY83SC]

Perhaps the lower pressures put a bit too much heat into the tire. Waiting on the "experts," like you. And hope they do say that "Kumho will send you a new set!"

[D Hanson]

Looks like you picked up a layer of hot rubber from the road surface. Although I doubt that happened, that tire looks aweful to me.

[MY83SC]

HMMMMMMMMMMM....Friday night...The "track Pro's" must be out and about.

[jluetjen]

Is This Blistering or Is The Tire Bad?

In my opinion the answer is "yes" to both questions. That's not "pick-up" which looks like lots of warts on the surface. That's a blister which suggests that the temperatures were hot enough that the tire materials started to delaminate.

That tire is about ready to start it's new career as a track-side safety device. I'd never put it on a car again except for display purposes.

[Tim Stevens]

I would also trash the tire. Also do not expect a thing from Kuhmo. A friend of mine had two heat cycles in the new Ecsta’s and the tire came apart on track and put him into the wall. $10,000 damage to his 993 and Kuhmo did not even send him a new set of tires (not that he would trust them again – but the offer would have been nice). Have fun at the track today – but if you have another set I would run them.

[126coupe]

I did the same thing at willow springs, you must be going faster
Was the tire shaved? Too low of pressure, go up 1-2 pounds, more Neg camber maybe