It mostly depends on the track layout and how tight it is or not.
Secondly: You need to be honest with yourself on how good your batteries are and how free your drive line is.
Third; Can you or your set up retain corner speed?
And lastly; How light your car is.
Temp of the motor is a good gauge of where you are but don't get caught up in what is too high or not (Unless you are running 220*F+)
If you are afraid to push your limits, you will never find them.
With my TB03 I have run clear down to 2.9 and as high as 3.7 in RCGT. My car weighs 1402g and the drive train is very free so I can get away with some low FDR numbers. I also ran 40C batteries back then and now will be running 65C. Yes it makes a difference, quite a big difference. I also was not afraid to run my motors around 200*F. The one and only 17.5 motor I have used is still running very strong and winning races in on & off road...... Fantom
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