Associated Sonic 540-M4 Modified Motor 7.5 DE ASC27490

Thanks to input from our international racing team, the Sonic 540-M4 Driver Edition was created! The 540-M4 Driver Edition is technically identical to the standard 540-M4, but is instead equipped with the popular #27447 rotor. This rotor is the lowest strength option, which is reported to improve throttle feel and consistency, resulting in better overall race times.