To fix mid-corner understeer, you can try:
Softening the front springs
Stiffening the rear springs
Adjusting the anti-roll bar softer front or stiffer rear
Toe-out in the front also toe out in rear can help loosen the car
Caster adjustment lower for small tracks, higher for fast tracks like Daytona.
Lowering ride height in front raise the rear
Camber adjustment
Raising the rear roll center height over the front can help aswell
Do small changes and try it. You might want to check out my tuning page for tips.