Get a Checkpoint in there. I know they do a 10x2 off road motor but I think they also do a 12x2. One of my mates borrowed my DF-03 for racing at Canterbury on monday, he stuck a 19 turn Checkpoint in and proceeded to rag the car round the track during practice until it was virtually flat (running a 4900mAh Trakpower lithium!!) and the motor was still nice and cool.
Very powerful motor as well.
-Steve