rod_b i run the reedy qm 19 turn in my xxx t. this motor gets its power from torque. with that said, you need to run between a 20 to 22 pinion depending on wheather the track is small and tight or wide open. the mistake that many people are making with the reedy kryptons and the qm 19 is they are gearing them like they would if the motors were like what they normally run. basiclly you need to go around three teeth larger with 48 p gears. gear it up and if it is tuned right, people will think you are running a 14 or 15 turn.