We just returned from the tracquest event at VIR where we had a blast (especially after it stopped raining on the second day). My nearly new set of Michellin Pilot Sport Cups were terrific in the rain but on day #2 with outside temperatures rising into the 90's my tires quickly felt slippery and my car felt unsettled. I checked the hot pressure and it was 33f and 35r as the Michellin manual says it should be. The tires were not shaved rather just installed and put into service.
Has anyone else experienced this? My son was with me in his Jetta, also fitted with the same tires and he did not experience these issues. Any suggestions or feedback?

 

I ruptured my left rear tire under similar conditions. It was a Pirelli, but I bet you can get the same type of good help I got, if you call Michellin's racing division. See my post by searching: "Warning: pirelli P Zero Corsa tire pressure" I got great results from a new set of Pirelli P Zero Corsa tires.

 

Dave,
In club racing on DOT tires we always try to get a good qualifying lap in on one of the first two or three laps. R compound tires get greasy pretty fast when they are pushed hard. You just need to adjust your driving style on the fly. In a stock car your problems are likely made worse by the weight of the car and a lack of camber which may be overheating the outside of your tires.

On the other hand, the up-hill esses are all the more exciting on slippery tires don't you think?
Jim

 

I guess that's the problem exacerbated by the hot weather I am sure. I ran at Lime Rock and had no problem. It was alot cooler and the track is slower.
Your comments are helpful because I thought maybe something was wrong with tires or pressure.
Regarding the esses, I found entering the roler coaster and hog pen to be the real heart stopper. Got a little sideways at the bottom and caught the corner worker out of the side of my eye grabbing for the flags...........but he didn't need them. Thought it was over for a second.

 

Dave,
I love that track. The club race last year was on the same weekend as the Grand Am series. It was great fun. The GA Cup 996s were running lap times around 2:07 or 2:08. My co-driver in the enduro ran a 2:09 in my 996 with a full tank or gas. Too scary for me.

As for tires, I think it's critical to keep a very close watch on your tires. Take hot pressures after every run. Inspect them after every run. Remove and inspect every three or four runs. Take tire temps if possible. You want your tires working properly in situations like you described. Congrats on foiling the cornerworker's plans.
Jim