KV rating means RPM per volt. So if you have a 7.4v LiPo and a 2200KV motor, in theory it should top out at 16,280 rpm. It's related to the number of turns in the motor. More turns mean lower KV. Higher KV motors have fewer turns. The Torque is opposite, the more turns or the lower the KV, the higher the torque of the motor is going to be. If you want a higher torque motor, you go with a low KV, If you want a high speed motor, you would chose a high KV. Neither high or low KV is better than the other, they are just used to accomplish different things. It all depends on what you want.
Last edited by pensfan2987; 10-02-2011 at 05:34 PM.