Final drive help
Turbo Mini Forums

Hi everyone
I am in the process of rebuilding my gearbox I was wondering what final drive ratio I should go for? it is going to be my daily drive and I go on the motorways quite often. I currently have 3.44 final drive. my engine spec is.
1293 turbo T2 turbo with 7.5psi boost
a plus primary gear
37-29 teeth drops gears
I am going to be fitting minispares heavy duty gearset with these ratios
1st 2.583
2nd 1.644
3rd 1.250
4th 1.0

What wheels/tyres ?

Smaller the wheels, the taller the diff you'd want ( numerically lower )

I did a load of miles in mine many years ago with the 3.1 diff and 13" wheels. Many times I'd have liked a 2.9...although 1st gear was a little tall even with the 3.1

However, it made 4th gear bearable on long journeys

Always a compromise.5 gears would be nice ( or 6 )

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

I have a set of 12 165/55/10 but I might go for 10s.

I ran 10's with a 3.2 diff and .958 ratio drops making the diff a 3.0 and found it a good compromise.

This may be useful http://www.guessworks.co.uk/Tech/ratio.htm


Shane