For most brushed motors out there 140-145 degrees is the limit and not the 160 degrees of brushless. Some of the super fast mods (under 10t) will want to be kept cooler. A lot of how hot you want the motor is determined by the tracks you run. If you run off road or on-road road course track you will want to try and keep it under 130. If you are bashing or running pan car you can push the 140 limit. Just remember that the more times you push the temp the faster the brushes are going to wear out.