Kris,
Are you saying that the car is pushing really bad? Or are you saying it is a mechanical problem?
If a mechanical issue:
I would check the steering system first. Look for worn, bent or broken parts.
Check the front suspension for binding, bent shocks, bent, broken or worn parts.
Check the rear end for binding, bent shocks, bent, broken or worn parts.
If a handling problem:
Then you need to look at your set up.
Steve