Surely it is torque and a good suspension setup you need. BHP ok at top end and power/torque great in a straight line but best drivers do not always have top power ratings. Get on a test track and get taught how to drive the car, get your suspension sorted out properly, ensure your brakes are good, lose the excess weight if you need to and then look at going for the big power. There is so much you can do just by sorting the suspension out and learning how to drive your car