Not trying to be rude, but judging from your comments and your dissatisfaction with your times, I think your money would be much better spent on improving your driving chops than on your car. Consider that a guy in a stock car was 5 seconds faster than your modded car. Sounds like your problem isn't with the car but the driver. Fix the driver and it will be much easier to figure out what's wrong with the car.

I hope you take this as constructive rather than destructive criticism.

Regards,
Alan