the motor you are running pulls a lot of amps and this causes heat...MGM controllers hardware wise are excellent and the software has gotten better almost as easy as a CC, like Brian I am very anti fan, IMO if the ESC is desgned right it shouldnt need a fan and with a fan all you are doing is cooling off the case. The interior of the component stays hot....heat is being generated in the center and goes outward and if the tempreture is higher that is trying to leave it will keep the cooler air from going any further.