To correct stability issues I recommend a complete suspension check. Check the following:
1) check all suspension parts for excessive play. 2) check and refill shocks if needed. 3) check all bearings/replace if needed. 4) if you have a setup board, check droop settings, camber, toe, caster and tweak settings. 5) check that your car tracks straight: center your steer nuetral setting/front tires so the car goes straight. And finally, check that you have the right tires for your track.