[SpEEdyBL]

The sidewinder may not be able to handle the feigao 8s, as it uses more power than a 5700 which is the limit. kvs are misleading when comparing motors with different size rotors. You could gear the 8s the same as you would gear a 4600 for the same top speed, but the 4600 would still be more efficent. Although you can argue that you would get more torque out of an 8s that way, why not get a 5700 and gear it down to get that torque.