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Final Drive ratios
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Author:  runkthepunk [ Tue Nov 10, 2015 9:26 am ]
Post subject:  Final Drive ratios
Hello all

I wanted to ask if any one is running or has had experience running the 2.95 or 2.76 final drive in their A-Series powered Coupe?

I currently do a lot of motorway travel, 200 miles a day 5 days a week :( and although I wouldn't subject the Coupe to that I am looking to do some long distance drives and possibly over to Oslo to visit a friend so improvements in Comfortable cruising speed, lower revs and increased economy all appeal. I am going for the GT part of the GTM name!

I am aware of the pros and cons of said ratios in the Mini but wondered if they were different if used in the Coupe? Hopefully the lower drag factor might improve the gains in top-end / cruising speeds where the Mini seems to plateau quite early perhaps due to boxy aerodynamics.

Anyway if anyone has any info it'd be much appreciated :)
Author:  minitici [ Tue Nov 10, 2015 2:16 pm ]
Post subject:  Re: Final Drive ratios
I had a 3.1 on 13" wheels with a 1380 and I don't think I ever drove on top gear!

A 2.xx would be even worse.
Author:  runkthepunk [ Tue Nov 10, 2015 4:25 pm ]
Post subject:  Re: Final Drive ratios
minitici wrote:
I had a 3.1 on 13" wheels with a 1380 and I don't think I ever drove on top gear!

A 2.xx would be even worse.


Okay that's interesting. I presume you feel the car was too slow on accelerating? even running a 1380 it didn't help? I have a 1293cc so less power and torque than your engine.

Can you recall using it on the motorway at all?

What Final Drive did the 13" sports pack coopers run? I think I remember it being 3.1
Author:  runkthepunk [ Tue Nov 10, 2015 4:38 pm ]
Post subject:  Re: Final Drive ratios
I was wrong I have read that the cooper sports packs had a 2.76 FD

here is a Rover Press release quote I found online:

'Despite being the 'cleanest' 'A' Series engine yet, the 1997 Mini engine matches the power and torque figures of the previous Cooper unit, doing so at lower engine speeds. For lower internal noise levels, a 2.76:1 final drive ratio raises the overall gearing by 16% compared to the previous Mini Cooper and this, coupled with an inevitable weight increase of around 3.5%, means a slight reduction in 'on paper' performance. The figures, however, remain very competitive and the subjective impression of the power delivery is excellent'

With fourth gear now equivalent to fifth gear on many other cars and a third gear high enough to virtually achieve the 90mph maximum speed, the driving characteristics are very different. The 'overdrive' fourth gear cuts engine speed at 70mph from 3,888 rpm to 3,333 rpm for more comfortable cruising, while third gear now provides the upper range acceleration and overtaking capability.
Author:  minitici [ Wed Nov 11, 2015 8:31 pm ]
Post subject:  Re: Final Drive ratios
runkthepunk wrote:
minitici wrote:
I had a 3.1 on 13" wheels with a 1380 and I don't think I ever drove on top gear!

A 2.xx would be even worse.


Okay that's interesting. I presume you feel the car was too slow on accelerating? even running a 1380 it didn't help? I have a 1293cc so less power and torque than your engine.

Can you recall using it on the motorway at all?

What Final Drive did the 13" sports pack coopers run? I think I remember it being 3.1


It was off the cam at any legal motorway speed in 4th. - no acceleration to speak of.

The 13" wheels has standard profile tyres, not low profiles - which made the problem worse.
Author:  bubbleless [ Wed Nov 11, 2015 10:30 pm ]
Post subject:  Re: Final Drive ratios
I was amazed at the fact rover fitted really low ratio diffs, I used a 3.9 on 10 inch wheels and it pulled 90 in third, but it did very little mpg.

Here is a good article explaining all the aspects of the different diffs and the pro's and con's

hope it helps :)

http://www.retrominisltd.co.uk/index.php?main_page=page&id=19&chapter=20
Author:  guru_1071 [ Thu Nov 12, 2015 4:15 pm ]
Post subject:  Re: Final Drive ratios
don't forget that you can run really tall tyres on a gtm - your not restricted to the 175/55 ones that minis are

from memory the 3.4:1 that is in mine actually works out at 3.1:1 if you crunch the numbers

its fast enough and cruises fine
Author:  kano nordie [ Thu Nov 12, 2015 7:35 pm ]
Post subject:  Re: Final Drive ratios
I used to run my old Cox on low profile P7 13'x175-55, only a smidgen bigger than 10"x165-70 with a 3.4 diff and raced with it, in-spite of slightly taller gearing it went quicker around a track :wink:
John
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