Yes you are going to want a fan with any motor you are running. The more you push your motor the hotter it gets. Also cooling it with a fan makes it last longer. I am not aware of any of the "fast guys" running without one. Only class I can see
maybe not running a fan is USVTA but I still think most do it to help prolong motor life.
I would check out
http://www.rctech.net/forum/electric...hats-best.html