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blickling
Member
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Posted: Wednesday May 2nd, 2007 07:57 pm |
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Hello all,
Some time ago now I converted my Mainstream to 10" wheels and have subsequently fitted a centre binnacle (an Ebay purchase and probably from a Mini 1000, as it is a 90mph one). My question is, what final drive does a Mainstream have, out of interest (I known I should be able to find out easily myself with a bit of reading-up, but have not got the time with the kids), and what would be the best final drive for my engine? The engine is essentially a standard specification, but with a Minispeed Stage One kit fitted. The car is not used for long journeys, just blatting around the Norfolk A and B Roads on weekends, when family allows! Any advices gratefully received.
Richard 
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taffy1967
Member
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Posted: Thursday May 3rd, 2007 12:00 am |
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The standard Mainstream Cooper came with a 3.1 final drive, which is slightly high and long legged so it's quite acceptable at motorway speeds.
But the final drive of choice is probably the 3.44, which provides a faster take off and more zip through the gears too.
Strangely only the 1990 versions of the 998cc engined Mini Flame Red, Racing Green and the Check Mate Limited Editions got the 3.44 final drive, where as all Mini models (except the Mini City E & Mini 25 LE which got a 2.95 I believe?) from 1982 went 3.1, including the Rover Coopers too when they were launched in 1990.
Of course from late 1996 the Twin-Point/MPi Minis were given even higher gearing again.Last edited on Thursday May 3rd, 2007 12:06 am by taffy1967 |
DaveShreeve
Administrator
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Posted: Thursday May 3rd, 2007 12:13 am |
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You should have a 3.105:1 FD. Don't think any of the 10 inch cars got higher than 3.44:1 without specialist intervention. Think I'd stick with what you've got unless you want to hear even more revs from the engine.
NB 'higher' - gives higher road speed at same engine revs, similarly gives same road speed at lower engine revs. 3.105 is higher than 3.44.
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DaveShreeve
Administrator
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Posted: Thursday May 3rd, 2007 12:28 am |
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Taffy, apologies for duplicating most of your post. It wasn't there when I started but I'm watching TV at the same time.
Not sure about changing to the 3.44. Mainstream is more spec'd to pulling the 3.105 rather than revving on a 3.44. Change to 10's should have given a bit more zip than original 12's.
For info, Spi Cooper went back to a 3.21:1
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blickling
Member
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Posted: Thursday May 3rd, 2007 05:36 am |
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| Thanks both. One thing I suppose I ought to do now she has 10" wheels, is get hold of an appropriately calibrated speedo if I remain with the original final drive? Richard.
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taffy1967
Member
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Posted: Thursday May 3rd, 2007 01:57 pm |
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Taffy, apologies for duplicating most of your post. It wasn't there when I started but I'm watching TV at the same time.
What on earth were you watching at that hour?  
Don't think any of the 10 inch cars got higher than 3.44:1 without specialist intervention.
But Minis were still riding on 10" wheels in 1982 when they first got the A+series engine fitted and the final drives were changed to 3.1 (or higher for the City E, thus completely killing the performance) to aid the economy of the Mini City E and Mini HLE (just prior to the Mayfair being launched).
Then the Mini range switched to 12" wheels and 8.4" discs in October 1984, but I've heard that the "Mini 25 LE" was the first to be equipped as such.
Anyway here's some documented evidence: -
http://www.roblightbody.com/mini/brochures/1983/index.htm
http://i97.photobucket.com/albums/l236/taffy1967/Mini%20Stuff/Mini25CelebrationSouvenirProgramme.jpgLast edited on Thursday May 3rd, 2007 02:20 pm by taffy1967 |
DaveShreeve
Administrator
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Posted: Thursday May 3rd, 2007 02:32 pm |
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Taffy, the hour was more like 15mins! I was referring to Coopers rather than the mini range.
Richard, tyre change would cause speedo to read about 3mph fast - if it was correct on your 12's. As source of speedo isn't known I'd suggest either checking against another vehicle or timing over a measured mile. If recalibration is required I think Speedy cables had a process on their web site so you can provide them with the required info.
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taffy1967
Member
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Posted: Thursday May 3rd, 2007 02:39 pm |
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I was referring to Coopers rather than the mini range.
Oh right, well I must have confused the issue when referring to the type of Minis that were produced with the John Cooper Conversion in mind. Namely the 1990 Racing Green, Flame Red & Check Mate LE's with the 3.44 final drives?
and you can contact Speedy Cables here: -
Speedy Cables link
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Andrew1967
MCR Member
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Posted: Thursday May 3rd, 2007 03:01 pm |
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Don't email them though as you'll be lucky to get a reply. No-one ever bothered to reply to two emails sent last year regarding overhauling my S speedo  Last edited on Thursday May 3rd, 2007 03:08 pm by Andrew1967 |
NZmember
Member
| Joined: | Friday January 11th, 2008 |
| Location: | New Zealand |
| Posts: | 3 |
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Posted: Thursday January 31st, 2008 08:38 am |
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Blicking
How far did you get with the speedo correction for your Rover Cooper? I went down this route myself many years ago swapping from a 3.1 to a 3.44.
If you retain the original "Clubman" style speedo pod of the Rover Cooper you get a different solution to using a pre-1980 centre pod.
See this info from MiniSpares:
Prior to 1980, matching FD changes to speedo readings was done by fitting a different speedo, an expensive way of dealing with the problem. After this the mix ‘n’ matching went on in the gearbox. More specifically the speedo drive spindle and pinion. So dealing with the easiest one first, fitment of any A+ gearbox with a 3.44 FD to a pre-A+ powered Mini, you need to fit the spindle and pinion out of the pre-A+ gearbox. Simple. If any other FD is fitted, it is easier and cheaper (in the long run) to get the speedo re-calibrated. Now the multiple choice option...check out the relevant table. This assumes 10” wheels and 12” wheels are retained where fitted as standard, but is reasonably accurate for 13” wheels, as the rolling circumference is very similar.
Speedo drive spindle and pinion data -
Tooth count - Tooth count -
Final Drive Ratio Pinion Colour Part no. Spindle Colour Part no.
All pre-1980 17 white 22A1881 6 none 2A3720
3.44 16 green DAM2905 6 none 2A3720
3.2 18 red TXD1006 5 red TXF1004
3.1 16 green DAM2905 7 blue DAM6028
2.76 15 black TXD10004 7 yellow TXF10001
Another part of the issue is the new spindle drive can have a different fitment to your existing cable and will require pinching up to fit.
Del
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