If it hops around tight corners on the ground with a spool its due to the outer wheel away from the apex turning slower than the other. Try using less traction compound on the front tires if using any at all. The slower wheel should slip a little until it comes out of the corner. If it doesn't vibrate off the ground with the wheels turned full right or left or with the wheels pointed straight ahead, its cornering traction induced. Its also the reason it will not happen with a diff or one way which both allow the front wheels to spin at different rates.