24 replies to this topic

[Dale_]

Hello everyone just testing ground here unless anyone can point me in the right direction?

Basically I'm just looking at making the gears longer in my mini. I know nothing about gear ratios. But I want to make the gears longer without sacrificing acceleration. Can this be done?

If so can I so it but just changing the gear cogs? Or do I have to change the gearbox?

Thanks in advanced all :)

[Carlos W]

You can change the diff which would change the gear ratios BUT you will sacrifice acceleration.

 

What are you trying to achieve? 

[Moggyton]

Lowering the final drive ratio should help. Do you know which final drive you have?

[Dale_]

I would just like to have longer gears. I don't know what ratio it is but it's a pretty standard mini equinox :)

[Tamworthbay]

Lowering the final drive ratio should help. Do you know which final drive you have?

but he doesn't want to sacrifice acceleration.

Sadly the simple answer is no - you can have low revs at higher speed OR good acceleration but not both. there is an answer in that you could get a bespoke set of ratios made up for something like the Jack knight 5 speed box but that would probably cost two to three times the price of a decent mini.

[Carlos W]

There may be a compromise somewhere, but why do you want longer gears? Fuel economy? Noise at cruising speed?

[Dale_]

Ok say I want long gears and acceleration, is that possible? :)

[Carlos W]

Ok say I want long gears and acceleration, is that possible? :)

 

You'd have to stay in lower gears longer.

 

The issue is, you may end up in a situation where you end up having to drop down a gear going up hills where you could've driven up in 4th previously. The engine may not have the power with longer gear ratios

[nicklouse]

Ok say I want long gears and acceleration, is that possible? :)

anything is possible but at a fair price no.

 

what you are asking for is as above an extra gear.

[Cooperman]

In a word "no". The way to get 'longer', i.e. higher, gears is to fit a higher ratio final drive. This in itself is easy and not particularly expensive, but acceleration will be poorer and the higher you go with the FDR the poorer will be the acceleration. Competition race & rally Minis have very low final drives to maximise acceleration, but they really have to rev, like to over 7000 rpm, to get maximum cruising speed.

A Mini is not now a high-performance car, it is a 55-year old designed classic car with all the limitations of classic cars and it has to be accepted as such.

[Dale_]

Yeah I honestly get where you are all coming from, so if i get a lower final drive I get better acceleration and a higher drive gives a higher top end but sacrifices acceleration. So if I was going to go all out on acceleration. But still wanted to be able to get around 80 out of my mini what would I be looking at doing?

Thanks for all your time guys! :)

[jaydee]

A 1275 engine will be able to do 80 easily with a 3,1 diff which is not that long to kill acceleration.

Have a play with this to get an idea of ratios and speeds

http://www.guess-wor.../Tech/ratio.htm

Edited by jaydee, 22 October 2014 - 09:58 AM.

[HarrysMini]

Have you looked into 5 speed boxes? They have essentially a normal gearbox with an overdrive gear, which means that you have say a 3.44 FDR for 1-4th gears, and a 3.037 FDR in 5th. So you have the acceleration of a fairly low FDR, which the lower engine cruising speed and economy of a slightly higher FDR.

 

http://www.minispare...px|Back to shop

[69k1100]

Depends on your budget, if you want "longer" gears and acceleration adopt a lower ratio and uprate the engine to make up for the loss in gearing.

[Cooperman]

Depends on your budget, if you want "longer" gears and acceleration adopt a lower ratio and uprate the engine to make up for the loss in gearing.

I think you mean a higher ratio. A lower ratio means shorter gearing and higher revs for a given rpm.

 

Note that the original 998 Cooper had a 3.76:1 FDR and would do around 88 mph which was just under 6000 rpm in top. I know I used to cruise mine at 80 mph which was just over 5000 rpm. One mustn't be aftaid of revving a Mini. That is what cars were like back in the '60's. If you want to cruise like a modern car, then buy a modern car. A Mini, whilst great fun and a wonderful iconic car, is old in design an d must be seen as such.