This is something ive wanted to try and get a bit of a clearer understanding of for a little while now, as it's something im not too sure about.

My understanding is (rightly or wrongly?) that the final drive ratio ultimately relates to the number of turns the motor makes to the number of turns the wheel makes?

ie. the final drive ratio of a S2 is 3.82, so the engine will do 3.82 revolutions to the 1 turn of the wheel, am I understanding this correctly?

The final drive will dictate your maximum speed in each gear, in top gear the standard ratio of 3.82 gives 153mph at 6500rpm (195,45,16 profile tyres) while a lower ratio of say 3.4 in top gear would give you a speed of 172mph at 6500 rpm (195,45,16 profile tyres).

So presumably it is a bit of a balaning act between, how much acceleration you want, and how much top speed you want. I assume BHP is going to play a big part in your maximum speed as otherwise you could put the final drive on a standard RST (132bhp) to say 3.1 and theoretically achieve 188mph (not going to happen - the horsepower just insnt there!), and also the shed like aero dynamics of the S2 isnt really going to do you any favours!

So, assuming you had the horsepower (say 300+ bhp), what would be a good final drive ratio (does it come down to your driving style? ie is it going to be a track car / road car) and am I grasping the concept???

I would be interested to know what the final drive ratio's of christians S2 was, and what sunny's 179mph FRST final drive was.

Sorry if I went on a bit there!