jrgordonsenior

OK 20 cold is minimally OK as long as you allow them time to get up to temp without beating them up. Scrubbing them hard at that temp, especially if they're S9C's, could be the cause of your failures.

11lb pressure gain is considerable. Are you using N2?

dwe8922

It was the green rear; described as their flat track and speedway tire. He said they recently replaced it with an "N" tire, which tolerates even less camber. Apparently, the sidewalls have gotten stiffer with each version, reducing the camber they will take. He also said they had seen that failure from cars being rolled around the shop with a deflated tire.

I'm pretty gentle warming the tires up (or atleast I thought???). I don't really sway back and forth, and I generally stay off the curbs as a rule to be easy on the aluminum bits. David Murry told me to warm up tires/brakes by using the brakes. Yes, I'm using N2. I think the track temps were over 140 deg someone said at VIR. The Michelin book says 19 psi is their cold minimum.

Cory - I finally got a chance to look up the Mini vs. Porsche stuff on youtube; pretty cool stuff!

PedroNole

In my experience, if you tell Michelin that your pressure was within specs, they will tell you it's camber, if you tell them the camber is within spec, they will tell you it was a valve stem, if you show them the valve stem is ok, they will tell you it's a rim problem, if you show them the rim has no problems, they will tell you it's a rub issue, if you show them it's not a rubbing issue, they will tell you you overheated it, etc, etc, etc. You will NEVER get them to admit to a failure...

I've had the same problem you've had and I've had it on front and rear tires. As good as the Michelin's are, sometimes you get some bad ones. That said, if you bought the tires from someone else, not new, then you never know what the tire has been put through.

Larry, the 996 Cups take (and like) a lot more camber than the GT3.

wanna911

Slightly related I know of 3 996 Turbo's including my own (+ Tom Kerr & Accelerator) that have blown about 10-12 left rears between all of us over the past 2 years or so. All running 63" wings and about 3* rear camber on 1k+ lb springs (obviously much heavier cars though). I know Al (accelerator) posted a thread a while back but the funny thing is that only slicks have blown, no R6's, no Nitto's etc.. Michelins, Hoosiers and Yokohamas. We've blown them all and many don't make one day. Always left rear. Tom's car I believe has full cup suspension on it and the other two have ranged from stock to everything but uprights and the same result every time.

Obviously I don't have an answer, but this is quite frustrating.

coryf

What size diameter were the tires? 650? The turbo can't run a tall enough rear tire due to the ducting for the intercooler. (At low ride height) The factory started running 680 diameter in 2002 on the 996 cup because even at their weight and realtively low hp the rear tire couldn't take the heat and loading. A heavier and more powerfull turbo car would definately have a problem if driven hard. We have run up to 710 rear diameter tires on a 997 cup.

Larry Herman

Are you guys still running rubber bushings in the suspension arms?

wanna911

I've personally run 650 and 680 and I think most have been in that range. The 680's were too tall for the TT IMO.... But even the 650's are going, and they all just separate on the inside tread.