Clutch and FD thoughts
Turbo Mini Forums

now the mini is pretty much back together, the thoughts are firmly on getting the metro built up and running.

To recap, the engine spec is 1293 with avonbar ph2 cam, Head has been suitably fettled too - all running megajolt. Turbo for now is going to be standard T3 with cosworth cooler. Gearbox is all Minispares SC with challenge drops. No specific power but lets work on the basis of a potential 150-160bhp for now.

My first thoughts are with the clutch. I have a steel ultralight flywheel, paddle plate and double grey spring sitting on the shelf that have very little use (originally fitted to the mini but removed to fit an RTS). The car is not road going and ideally I'm going to use it for drag and sprinting long term. Now thoughts are with killing thrusts and therefore considering a lighter spring or alternatively going for another RTS on a lightened verto. Also thinking of the modification to allow oil feed to the thrusts...........

Thoughts also turn to final drive; I spent a fair bit of time researching a while ago and ended up opting for the 3.1. I know the challenge cars ran 3.9s so at the other end of the spectrum. on the basis of the strip, the 3.1 looks a good bet but not sure it may not be a little long for short sprints and hillclimbs (I appreciate every circuit is different but trying to get a happy medium for now). Again any thoughts?

Hi Rob,

Im running 3.1 FD and an RTS with AP fast road plate. Power is very similar too, I have had no issue with the clutch slipping and the pedal pressure isn't too bad. The mini is very responsive and does run out of legs quickly on the road, Benross did advise on fitting a 2.9 FD with 10".

My issue is the 4 pin diff locking up on a emergency start, it is a minisport one so this is something else to think about.

I checked the thrusts the last time I had the engine out and there was no sign of damage, the two plates in my RTS are a uprated blue dot AP and 1000.

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

Rob, 3.1 is far too long. Gear it so its flat out over the 1/4 mile. I'd say a 3.7 ish would be more like it. Again if sprinting you want it to accelerate as quickly as possible.

Tom, I'd have said the same thing but when researching, quite a few were suggesting they were topped out going over the line.

My initial thoughts were perhaps around 3.6 before the first round of investigation.

I know I'm probably looking for a jack of all trades diff and going to compromise somewhere - the shorter one makes more sense in my head...........

If its a pure competition car then build the motor so it will rev. The DON is geared so its flat out at the 1/4 @ 125mph which is the limiter in top on a 3.9

Also, its easier to use a taller tyre on the strip if required. its more of a ball ache changing the FD for a sprint or hillclimb.

mmmmmm, not sure what the power band is with my build; assuming a redline of 6500, a 3.7 would be topping out around 100

Rob what's your wheel size and tyres ?

Currently on 12's with 165 yokos. Could also run 13's with a variety of tyre combos

I thought flans metro ran 13" ronals? I'd go with 13's on 175/50/13's and a 3.6fd personally.

If something is worth doing, it's worth doing half of.

Currently on 12's john (well im pretty damn Sure they are!).

Tempted with digging out a 3.7 and trying it. Got a shout out locally wih some guys wh actually compete where i'm hoping for some guidance

The look like 13's in the pic you've uploaded to Facebook

If something is worth doing, it's worth doing half of.

I've also got a grey clutch cover with little use

If something is worth doing, it's worth doing half of.

John, i think your right, all online info suggests the ronals are all 13's. Bit of a senior moment.

All proper Ronals were 13''. We also had a set of similar 12'' wheels, but they were not Ronals...

Them that you had off me? pretty sure they were 100+

On 5th Oct, 2014 Shauna said:
What that's crazy, you go commando hahaha! How heavy is your helmet ?

IMO with the spec you have go with 3.4 or maybe at a push 3.2FD other members may disagree

it wont run out of legs and you will give the turbo time to wind up and do its job

I lad.

just been doing a bit of research on what the car used to run; I was pretty sure the regs were for a 3.9 diff but having looked last night, it is open so could have been a number. Will need to drop Flan a note and see if he can guide me a little.....

for some reason, I also thought they ran an STR930 cam which would have been wild for a turbo motor. again, misread the rules - they refer to an mg spec cam but an str931 crank

will be heading up hopefully later the check the wheels and start getting a plan of action

I'm sure its 3.9 diff Rob. Haven't looked at the rules for years.

I thought that was the case Jason but when i checked the regs last night, the diff ratio in class C was open. Perhaps a change to ket thrm compete with the 16v cars?

Seem to remember Jon saying the first gear on challenge ratio was quite tall...so 3.9 diff would help.

I'm still saying 3.6/3.7

If something is worth doing, it's worth doing half of.

I'm heading that way john