post wha your set up was i use a 1 cell in boosted racing also along with the new MMM 17.5 motors.
the other guy here has also used the 1 cell motors 3.5 and have had very little troubles, i was smoking motors a while ago and it had everything to do with the programming in the speedy.
i race on a large open asphalt track MMM geared at 5.2 with the 323 software with a GT2.1 speedy