I moved my batteries from the center of the car to the sides. I'm running a 6s setup, so I have 3s battery packs on both sides of the car.
you are doing high speed straight line runs ? if so, take out your camber so you have full contact of the tyre on the ground. drop to 32Sh also. what KV motor ? 6S is a very agressive setup, you will light up the wheels no problems no matter the setup. specially hammering the throttle from a standing start.