i have not used a hvmaxx motor with a mamba max recently , but i have ran a hvmaxx 4.5 motor in a e-revo with a mamba monster , ran very well , just use novaks rec. gearing , with a 12 tooth pinion it was good 135* @ the end of motor and 125* on the big heatsink , with a 13 it went up to 155* at the end bell and 145* on the heatsink, so gear accordingly

http://s170.photobucket.com/albums/u...t=MVI_1928.flv

http://s170.photobucket.com/albums/u...t=53898a05.flv