E90 328 Loss of power at Watkins Glen

I was participating at a track day event at Watkins and experience a loss of power after about 3 hot laps. I didn't experience this in the morning session when it was about 40 to 50 degrees. In the afternoon session (72 degrees) the engine would run fine until about 3 laps into a session. Coming off turn 11 onto the front straight in 3rd I put the pedal to the floor and could feel the car nose over. I lifted just a little and the car would start pulling again. Put the pedal to the floor and again it noses over. I tried up shifting to 4th but it did the same thing. As long as I didn't put it to the floor it would continue to pull but not very hard.
No warning lights at all. Nothing seemed out of the ordinary.

After our classroom instruction I headed out for my last session and it ran fine unitl about 3 laps in and it does the same thing.

It was a perfect day not to hot and sunny.

Any ideas????

Never had this problem with my Mustang. But I never had this much fun driving either.

Thanks for any help!!
Larry

This is a total guess, but could it have been so warm that the engine was starting to ping and so it retarded the timing? I have never had this happen so I may be way off.

Thats a possability I hadn't thought of. I would hate to see what happens on a really warm day. I hope to go to Waktins at least 3 more times this summer.
Thanks for the feedback!
Larry

Larry, what tires were you running at Watkins? I ruined by RFTs at a car control clinic! I am replacing them on an E90 328i and would like to take a track school at Laguna Seca. Thanks, Chuck

Chuck,
I am running the stock RFT Brigestone RE 050 II A tires. I have run autocross and track days with these tires without any issues. I usually start with pressures of 40 to 45 psi front and rear. I tend to run the rear a little higher to get the car to rotate since it has a under steer built into it and made worse by the 225 to 255 stager.
I have purchased rims and am planning on buying some R compound tires eventually. I am building another car so money has become and issues.
Hope this helps you!
Larry