4.1 and above gives you greater acceleration at the expence of top end, while 3.9 and below are slow off the line but give a higher top speed. General rule of thumb is that you want a 3.7 or 3.9 for your Turbo car, and 4.1 or 4.3 for your Atmo car.
You can check by telling us what's on your car's build plate (all the numbers and letters) or by jacking up the rear of the car and counting how many times the tailshaft turns for one turn of the wheels.
Cheers,
Mitch.
Wed, 12 November 2003 07:57
