what is the best diff ratio?
Turbo Mini Forums

I originally ran my engine and box as standard ie 3.21 diff and it accelerated pretty well, but box was never right, so I changed for a 3.44, but again box died, so I am going to rebuild one of the gearboxes but not sure which diff is better. I want real acceleration not too bothered about top end, but which would be better. I know in theory the 3.44 would give me better acceleration, but if the engine is torquey enough wouldn't 3.21 actually be quicker because of less gearchanges? Any ideas?
Thanks guys
Sam (1975 mini turbo yellow as they come!)

I would wrote that if your engine is really that torquey, ie more than the std one, running without the ecu,I'm prefering the 3.1 dif, because even the 3.2 is a little short on higher hp's and torque, but if your choice is 3.2or3.44, use the 3.2, I'm quasi certain that a3.44 is undrivable when you are on good boost level and on the first gear,
cheers
fab

for info my actual box ( in built) is a 1000 cc quasi (cause unstressed), innocenti A close gears, with primary gears from a mpi using the turbo nose bearing and so primary case , this combined with a 3.1 dif and perhaps a 2.9 one if I find one.

The engine is standard turbo but am running without an ecu so the boost is constant 7 pounds. It was a bit of a handful with the 3.2 diff when it was running but never had it running properly with the 3.44 so may have been undrivable.

What size wheels are you running?

Team Racing

I will be running 13's eventually

maybe a 3.76 wold be better, that woudl give you a top speed of 97mph at 6200 rpm

Team Racing

so jimster you think that the 3.44 would be the better out of the two?

I will never use 13's on a mini, heaviers, no more grip and less handy, my best choice are 5.5*10 on 165 a008 or a032r (amazing how they last are gluing with the tarmac), depend how often you want to change them , or a048r 155/55/12 on 5.5*12,
about the diff it really a question of road /trac or mix, I just know that 3.21 is too long for trac, as I never used the fourth gear on trac days,
cheers

I'm running 10's, I'm going for a 3.44, but I have an lsd so I'm limited a bit on choice, also I have a much longer 1st gear (2.315:1 ) than most.

Team Racing

jim , shell wasn`t so sure on you having a much longer 1

Everyone knows that instructions only have to be read if the thing doesn't work....

how would she know anyway, we aint married

Team Racing