Gearbox For Track Work - Advice Needed!

[rob.duke 0]

Hi All,

 

First posting and first time on a forum so please go easy!!!

 

I currently have a Road/Track 205 Mi16 which I ran on a Mi16 Gearbox (Be1 - rev next to 1st) and found the gearing to be too long for trackdays, as it's been getting some work over the winter I decided to buy a 1.9 box in the hope that it would give me a better accelerating car. Sadly the ebay box buy turned out to be a bit of a dud as it won't go into 4th.

 

I now have the dilema of getting the 1.9 repaired or sticking with the Mi box, or making something from the 2 or getting something else?

 

Just wondered if people could share their views on what is the best way to go, the car is used mainly as a trackday car with the only real road miles covered going to and from tracks (although these can be quite far and I have a Nurburgring trip booked too) Is there a way to have a close lower 1,2,3,4 and a longer 5th?

 

I also have access to a diesel box, are they ever used or any good?

 

Sorry for all the questions, but it's a bit of a dark art to me.

 

Thanks for any help,

 

Rob

[Tom Fenton 1,542]

I use a 1600 gearbox in my Mi track car, its just about long enough for the longer straights you may encounter, e.g. Donington, Silverstone, up to Avon Rise at Castle Combe. Plus the fact it is an easy option as it does not require you to strip and build the box.

On the other hand it is nice and close and suits the engine well as it allows you to keep it on the boil without problem.

On the road it is tolerable for distance, it will sit at 80mph at reasonable revs.

There are some hybrid boxes that can be built using a combination of gearkit with Mi final drive, so this could be an option if you don't mind stripping both your boxes to make one out of the two.

[tri_longer 25]

On the road it is tolerable for distance, it will sit at 80mph at reasonable revs.

 

Really

 

I find 70mph (4000rpm) intolerable after a while and sit around 60-65.

[welshpug 1,661]

make something of the two

 

the 1.6 box Tom mentioned will give you the following gear speeds at 7200 rpm; 37 - 65 - 89 - 113 - 140

 

are you really pulling 140 up avon rise Tom

 

1.9 cluster on a MI16 F/D works well, though on the longer straights you may well find yourself flat on the limiter, 38 - 60 - 82 - 104 - 128

 

 

this will help if you want to have a go at taking gearboxes apart;

 

http://www.rallyparts.co.uk/cwp_change/

[rob.duke 0]

Bloody Hell that was quick!!

 

Impressed with the response.

 

It looks like a 1.6 box will be the best and simplest option.

 

I'll just have to take it on the chin being the slowest car on the autobahn on the way to the ring!!

 

Thanks Guys

[Pugnut 9 1 Cars]

doesn't the gti6 box give you similar ratios to the 1.6 box, but with an extra gear for the m/ways ?

[welshpug 1,661]

gti6 box is closer to a 1.9 cluster with 1.6 FD, not massively different to a 1.6 box though, but doesn't have the massive gap from 1st to 2nd.

 

mph/1000rpm (gti6) (1.9+1.6 f/d) (1.6) (1.9+MI16 f/d) (1.9)

 

5.8 - 9.1 - 12.0 - 14.8 - 17.8 - 21.1

5.8 - 9.1 - 12.4 - 15.8 - 19.4

5.1 - 9.0 - 12.4 - 15.8 - 19.4

5.3 - 8.4 - 11.4 - 14.4 - 17.8

6.4 - 10.0 - 13.6 - 17.3 - 21.3

[tri_longer 25]

I do know of someone who created a close ratio box similar to that sold by Quaife but from the standard gearing options available across the BE range of boxes. It creates as v. quick box, but the on road driving can best be described as nightmareish.

 

I'm sure there are some on here running a 1.6 with a 4.4 cwp from the MI which does compromise your cruising a little but nicer on the track.

[rallysteve 22]

I do know of someone who created a close ratio box similar to that sold by Quaife but from the standard gearing options available across the BE range of boxes. It creates as v. quick box, but the on road driving can best be described as nightmareish.

 

I'm sure there are some on here running a 1.6 with a 4.4 cwp from the MI which does compromise your cruising a little but nicer on the track.

 

How about the VTS box, how does that compare?

 

Steve

[Tom Fenton 1,542]

are you really pulling 140 up avon rise Tom

No, but with a good/committed run out of Camp and through Folly I have been well into 5th gear, probably 130-ish.

 

In the Mini I clattered the limiter in top up there, about 125mph. Then I required new underpants.

[welshpug 1,661]

 

must say, about 30 mph is the fastest I've come off Avon rise, and the wrong way every time

 

the vts/mi16 boxes give the following gear speeds in mph/1000rpm.

 

5.3 - 8.4 - 12.1 - 15.9 - 20.3

[rob.duke 0]

Those tracks are too far south for me to comment, any of you done Croft?

 

I think I'll try and source a good 1.6 box, I assume my Quaiffe ATB from my Mi16 box will still go in there?

 

Cheers

[petert 588]

If you've got a standard rev limit then the 1.6 box is certainly the easy option. But if you have an extended limit (say 7400) then a 1.9L set with an Mi16 final drive is a better option.

[Tesstuff 222]

All of Welshpug's gearing information is correct as long as you use the standard wheel and tyre sizes that came with that box as standard.

 

So you could get a lower or higher top speed than mentioned and gearing to match if you have a different wheel and tyre combination.

 

For example the 1.9 Gti box came with 15 inch wheels and a 185/55 profile tyre, so putting 185/50 tyres on would lower your top speed but improve acceleration. On the other hand sticking on some 16 inch wheels with say 195/55 tyres would make a higher top speed but lessen the acceleration.

 

You would be best to work out your planned gearbox gearing and then check it with your wheel/tyre combination and work out what your figures would then be.

 

Do you know the standard gearing figures for the D8 v6 as well Mei ?

[pug_ham 244 3 Cars]

Hi Rob,

Those tracks are too far south for me to comment, any of you done Croft?

I've done trackdays at Croft before running several different gearboxes over time & I think the easiest / best option for a gearbox would be the 1.6 GTI gearbox.

 

I haven't been there for a few years but would like to go back before the miserable locals manage to completely ban public trackdays there.

 

About the best gearbox I used there (but worse at other tracks) was the 405 SRi gearbox which has a very sinilar first thru third to the 1.6 GTI box & a 1.9 fourth with long fifth but I think I'd prefer to use the 1.6 box there as I've found it best suited to other tracks & driving to them.

 

Graham.

[rob.duke 0]

You are right about the locals, there is still a few days to be had but getting more and more expensive now! having to move further afield for fun, Cadwell next.

 

Thanks again to all for the advice