The go to oil when I raced was the classic red top Mobil 1 15w50. A car running hard in a racetrack environment can push oil temps WAYYYY up. Know what your oil temps are, and choose accordingly. Really high oil temps often show the need for better oil cooling as well. The OP's oil temps of 90 - 110 * C are not extreme at all. With an oil cooler, a robust 5w30 is adequate for street driving.
Originally Posted by Averroes
A 50 weight oil? [censored], you're not playing around are you ?
Originally Posted by rooflessVW
If I had a 370Z I'd always run at least a 0W-40. Maybe even a 5W-50 if I was feeling froggy.