I ran my 328xi at the Summit Point this weekend. Like rheemix I don't have any added cooling mods. I noticed on day 1 of the weekend, on the third set of runs I had some power loss I assume from the oil temps getting high. No other problems during the 7 set of runs I had throughout the weekend.
Tires will help alot. Do you have sport suspension?
Alpine White 328i xDrive||Carbon Fiber Grills||Carbon Fiber Hamann Lip|| Carbon Fiber Wrapped Roof|| Carbon Fiber Sonic Tuning CSL Trunk || LUX H8 V3 AE|| H&R Sport Springs || Adjustable Koni Yellows || 19" Breyton GTS Race Wheels