He wasn't trying to run a mechanical speed control with that 8 turn, was he? That would definitely fry something.
What kind of speed control was he using? You need to make sure that your ESC can handle your motor, otherwise you will have things heat way up, if not fry.
The reasoning behind that is, a lower wind motor (like the 8 turns you are thinking of running) put a much higher current drain on the battery/speed control than a higher wind motor, like a stock motor.
You need to have a speed control capable of handling that without getting too hot.