^ lol

to get more acceleration, there are 4 ways
1. you need more air/fuel this can only be done by bigger capacity engine or forced induction (as mentioned).
2. Lower gearing (as mentioned also)
3. change the bore/stroke ratio. Wider pistons with less stroke give more torque at the same capacity and RPM.
4. Lose weight

cost is prohibitive to do anything other than lose weight (from the car, that is)