Gearbox question
Turbo Mini Forums

Hi guys,

I have a metro turbo mini running approximately 120bhp which I use both on the road and on the track and do less than 2000 miles per year.
When I first ran it a number of years ago I ran the original helical gears but changed the drop gears for 1:1 straight cuts and put in a 2.76 final drive. This gave me great acceleration and good top end speed. However, a few years ago when I was driving it steady after just replacing the engine and gearbox gaskets the gearbox went bang when I tried changing from 3rd to 4th. The 4th gear and corresponding lay gear gear had stripped half of their teeth. The rest of the gearbox was in tact and looked fine (no scoring on the gears and all the teeth intact without any visible marks.
I took this opportunity to fit a set of straight cut close ratio gears and a 3.4 final drive. This is fine for short tracks, but is rubbish on the road as it is hard to pull away without slipping the clutch and the top speed is lacking somewhat in relation to the previous set up.
I currently have the gearbox out and I am planning on putting the original set up back in.
The question I have is should I re-use the old gears (1st, 2nd, 3rd) as they look fine or buy new? If I do re-use them, will they match up with a new lay gear or wear out really quickly? Obviously I will use new baulk rings, bearings etc throughout.

Thanks in advance.

I would have a look at guessworks gearbox ratio calculator and put your details in. Might just be that you need a different final drive.

I am confused as to why it was harder to pull away with the 3:4 diff?? It should be easier to pull away compared to the 2.7...

If you have the straight cut gears I would be wanting to use them as they should take the power better than the helical gears.

Dave the Cake

It'll be the ST ratios with taller first.

You could go for an MS Evo Gearset and 3.2:1 as a compromise.

In the 13's at last!.. Just

I've got the ST sccr gearset with a 3.1 fd in my 1100 and it is an utter bitch to pull away with - you can do 45mph in first !
It's on a par with or worse than trying to pull away in second in most cars...

Because first is so tall, the overall gearing when trying to pull away is higher despite having a shorter final drive.

Metric is for people who can't do fractions.

More emergency starts?

Ahhh I'll get me coat

Dave the Cake

Hmmmmm maybe I better sell that 3.1 cwp I just bought!

Got a st gearset. What would you guys recommend on 10s?

I'd a Tran X gearset in mine, 3.1 FD and 13" tyres.

Never had any issues with 1st, in fact it was great. A short first gear is pointless when you have some power.

Little over 50 in 1st, 80 in 2nd, 110 in 3rd

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

hmm clubman ratios and 2.95 is my plan interesting to see what people say about there experience
i do want the car for 60-110kph with the burst up to warp speed haha nice high way gears

I believe I have a clubman gearset and I was running a 2.95. I could hit just shy of 60 in 1st @7300 rpm

As Alex said a batch to pull off

Edited by eden7842 on 3rd May, 2014.

13.95 1/4 mile on a 2.95 fd. Carnt be that hard to beat!

Have run the tranx clubman ster with a 2.9 and 3.1. Using t3 turbos so a little slow off the mark. Better than just spinninv the wheels up. This gearset is very well suited to turbo application

Thanks for your help guys. Ill let you know what I decide and how I get on.

I'm running a MS clubman sc set with a 3.2 FD.

Hopefully will be running this weekend so will let you know the outcome of setting off or not.

Also on 10's

Does the ST sccr gearset have a tall 1st, which makes setting off a pig, or am i missing something !

Edited by lee.pb on 9th May, 2014.

What the mind can conceive the mini can achieve
MITP 2012 17.01 seconds 1/4 mile against "The Don"
MITP 2013 16.83 seconds 1/4 mile

think ill be happy with my choices by the sound of it, ive also got a lot of compression to pull the low end till boost rolls in

Clubman gearset uses the standard first gear. ST gearset has the tall first.

In the 13's at last!.. Just

Should have no issues setting off then

What the mind can conceive the mini can achieve
MITP 2012 17.01 seconds 1/4 mile against "The Don"
MITP 2013 16.83 seconds 1/4 mile

theres not that much difference beween the clubman and ST ratio though,

clubman

1st 2.58
2nd 1.71
3rd 1.25

ST

1st 2.54
2nd 1.73
3rd 1.22

Hopefully will find out today

What the mind can conceive the mini can achieve
MITP 2012 17.01 seconds 1/4 mile against "The Don"
MITP 2013 16.83 seconds 1/4 mile

Edited by Sprocket on 10th May, 2014.

No issues setting off with MS clubam set and 3.2:1

Clutch not too bad too Sprocket

What the mind can conceive the mini can achieve
MITP 2012 17.01 seconds 1/4 mile against "The Don"
MITP 2013 16.83 seconds 1/4 mile

Shows how much I know! Lol.

I thought there was a bigger difference than that.

In the 13's at last!.. Just

Not sure that gearbox ratios are on the curriculum here in the uk Veg. Although, if it was and I missed it, then it's me that needs to go back to school.

So, ST and Evo sets are pretty much identical. Was there not another gearset that included a much longer first?

In the 13's at last!.. Just

yes, a couple in fact,

the metro challenge set that had a 2.31 1st,
and also there were so JKD ones with 2.1, 1.75 or 1.69 1st's CLOSE!!!