This past weekend there were 7 Spec cars (SP1) on the new RR tires at TWS. All 7 of us had the tires delamenate, two of them severally. One had a 2" strip come off around the entire tire and another lost a 3" x 3" chunk. Most of the issues we the formation of a line in the tread but with the two described early we all stop using the tires and put on the RA1 tires. We felt it was a possible safety issue. The guy driving the car which lost part of the tread around the entire tire said the car was very difficult to handle. With the speeds at TWS it a prudent move to go back to the RA1. The issues were all reported before 5 heat cycles and all ofthe tires were on the cars correctly. It was in the mid 80's in College station.

I can report the RR is faster.

We ran at Fontana (Cal Speedway) which is a Roval with 8 cars and speeds above 120 mph with no reported problems with tires.
This is not a particularly hard track on tires but it does have 3 very big braking zones. One is from 120 to 45 mph.

In Feb I heat cycled mine and two tires were not mounted correctly and those two in a short session showed the splitting line. After 6 more heat cycles the splits were still visible, but less, now after another 5 heat cycles I don't see the splits but I do see a couple of small junks out of the tires from possible rocks or hitting gators.

See if all the tires with problems have the same or similar date codes, maybe they came from a bad batch, mine are 31/12 and 32/12. We can maybe look for a pattern from the ones going bad.

Sorry you guys are having a problem, so far I like the tires, they seem to be giving more confidence to some of the drivers to make passes in places they didn't before because of the extra grip.

This weekend the track temp had to be in the 130+ range in Phoenix, the track was feeling greasy with the high temps so we were having some sliding and it was predictable and controllable. I am still looking forward to seeing how many heat cycles they will do before needing to be replaced.

Good luck,

Tim, did you verify that they were mounted correctly? Date codes to the left on the front axle, and to the right on the rear axle. So far, my issues resolved with that. It seems silly, and it is fussy, but did seem effective.

Toyo is going to want to see those tires, particularly if it can be verified they were mounted correctly. Sorry to hear about this in any case.

I mounted Todd's (the thread starter) tires myself. They were mounted correctly. I've sold about two dozen RR's in the past few weeks. If I don't install them on the car, I mount two each direction and include a copy of the notice from Toyo with the tires.

Personally, I've only run two session on 944 Spec RR's, but it was on a BMW weighing only 2150# with driver. Those tires were run at TWS as well, but on a much cooler day.

I heard some reports of a couple of RR's delaminating at the NASA event as MSR last weekend, too. I know in one case, the tire was installed on the wrong end of the car. I don't have details on the other tire issues, yet.

I can provide source information to Toyo if they need to know the distributor I purchased the tires for resale from.

-bj

Can you guys put together some pics of the tires, and their mounting position on the car? I can then get them to the tire engineer at Toyo I am in contact with. It is especially improtant for those tires that lost tread. Toyo is going to want to see those tires, and if they were mounted correctly, also replace them (which they have done for me and others early on here).

It may be a good practice to verify mounting position on the car in some way moving forward, so we can keep track of what is happening when. If tires are losing chunks of rubber, mounted correctly, we need to get Toyo involved right away.