25 replies to this topic

[Grayedout]

2.9 on 10inch wheels with Stage 1 1275 and I love it !!!

Don't notice that much loss in acceleration but only 3800rpm at 70 mph !!!!

[Jammy]

I had a very similar set up to Minis84 with my 1425, 1:1 drops, 3.44 FD and 10" wheels running 165/70 profile. Acceleration was never a problem, and when I went out at a weekend I'd sometimes do 50-75 miles in a day on the motorway, would of preffered a 3.1 for that, since I think I could of lived with the tiny difference to my already impressive acceleration!

[Turbo Nick]

i swapped the 3.44 i originally put in my turbo because it was a pain in the arse on the motorway. i've fitted a 3.1 now and its perfect, something like 3700rpm for 70 in 4th now. with a 6k rev limit its 45mph in 1st, 65 in 2nd, 85 in 3rd, 100+ in fourth and it'll pull all the way to the redline in top too

[Sprocket]

I have the 3.76, which is awesome on the twisty country roads. The car rarely sees the motorways though and when it does long journeys, 60 is the cruising speed and noise and rpm is not much different if you were doing 70 with a 3.2. So i'm happy. Its blindingly quick off the lights.

[minimadjonesy]

got a 3.1 final drive and 10" wheels, accelerates well and will cruise quite nicely on the motorway! not sure of revs yet as i'm buying a counter from jammy next week but it drove to IMM last year without issues and at one point one of the other cars advised me that we had been "cruising" at about 85-90!!

[adammini]

I think ill change to a 3.1 or 3.2, would be a good compromise. I think it will be ok with my engine as it has enough umph to cope.
While im at it, I think ill pop in a X pin diff, just incase!

[kyle]

just had a new box put in my mini, and its got a 3:1 final drive. The box in it before was a Standard SPI box but would quite happily pull 70mph in 3rd now with the 3:1 diff, it only just does that in 4th and only using 4000rpm, wont go any higher :'( .What ratio diff would of been in there standard, also this one acclerates better until you get to 4th ie all the other ratios are lower and closer as well.

[Guess-Works.com]

Think std SPI's had a 3.1 as std...

4k @ 70 sounds like a 3.44 diff, which would explain the rapid acceleration 1st to 3rd, but the lack of OOmph in 4th sounds more like engine rather than gearbox...

[Dog]

So with 10's the accel is better than if you were running on 12's or 13's...
So i could get away with a 3.2, and still have fun down the lanes?

[Sprocket]

After a little more thought and looking at the Rover workshop manual, the SPI was a 3.2 diff, despite me thinking it was the 3.1. Thing is that you only have to change the crown wheel between these two as the pinion is the same 19tooth, size and cut for both.

[tomtic]

I think mine's 2.75 on my City E, and it's pretty awful when it comes to acceleration. Is it difficult to change to a 3.44?