I run a 1512 2d/f on 4s in my ERevo. It's a great setup for racing. I can run as long as I want with no fear of overheating. I ran a 30 minute main a few weeks ago and motor temps were in the 120's. It's geared for about 37-39mph.
hey im runing the Neu 1515/2.5d motor with a 16024 mgm controler and it runs at about 30 C is im runing hard in the grass for 20 min and im using two 8s a123 bats. so you really dont need to wery about over heating well atleast i dont. and if you where thinking about going 8s you never go more the 1/2 throtle on a track and its very hard to comtrole so i would stay away.