The 7L isn't really a good motor if you plan on going fast. You are limited to running only 2 cell LiPo for continuous running. Any more and something will puff. Running 2s2p on an X640 will get you nearing 40mph.

Many people don't understand. You don't match different cell counts with a specific motor wind. First pick the amount of cells you plan on running, then pick a wind to best run with that cell count.


Ryan