Wannago, if I may suggest: try dropping the rear tire pressure down to 25 psi and don't be afraid to to do a healthy burnout ( as in don't be afraid to create some real tire smoke). Also, try letting the tires spin their way out of the burnout box as opposed to simply taking your foot off the gas and driving slowly out of the burnout box to the starting line. ( Don't be afraid to be aggressive, the car can more than handle it). FWIW, I've found the Michelin PS2's seem to like heat in them.
Another item you may wish to try, is, putting a bag of ice on top of the engine after you take the plastic shroud off in order to cool "things" down. Everything you can do to counter heat soak is to your benefit. Ideally the top of the engine where you had the ice bag should basically feel lukewarm to cool to the touch.
When on the return road try turning on your A/C which will turn on both cooling fans and help to cool things down a bit .