The funny thing was when Drake and I went down the straight my Speed pulled on his GRP motor,.. so it was tuned well, but that dang JX21 would pull both of us easily. The JX21 was in a Mugen MBX6. Our track is loose most of the time so wheel spin is up, and run time is down, however I always get 9 min on my speed even when punched. How much did you pay for your JX21?