the "t" in 15t stands for turns. higher turns equals more torque but lower top speed, lower turns are the reverse. You want to stick to the higher turn motors in order to get the torque to drift, the 15t should be ok for it. For the future you may want to look at brushless esc and motor. Virtually no maintenance with brushless. Not sure if the rear diffs are locked (should be for a car stated to be a drifter) but if they aren't then you're going to want to lock them. putty works if you ever want to unlock them in the future but for a permanent fix use jbweld or get a solid axle instead and keep the original diff clean. A lot of drifters also use front one ways.