15 replies to this topic

[Chris.Williams]

Hello people.......
I've ordered a Vmax SC kit from Stuart, should be here in the next week or so.
Question of Final drive ratio, he recommends, well, more states that you can run a 2.7 FD with no issues...I currently have the standard A+ 3.444 unit that came with my 86 Metro lump.
If I go to the trouble of changing it I'll also fit a cross pin diff etc.
I guess what I'm really asking is, What ratios are people using and the results their seeing?
I have a mate here who runs a race mini, beltching out 140bhp, he's running standard box, drops and diff, done 4 seasons with no failure......so I was thinking of keeping things stock till I had an issue.....but this FD keeps filling my head with doubts on my decision.
Help a fella out.
Thanks

Forgot to mention.......95% of my driving is on open roads, 100kph zones.....I live out in the country.

Edited by Chris.Williams, 02 March 2018 - 06:47 PM.

[Steve220]

I'll be running similar power and found from having a drive of different forced induction minis that 3.1 works well!

[Chris.Williams]

I'll be running similar power and found from having a drive of different forced induction minis that 3.1 works well!

Thanks for that, are you running a Turbo setup?

[Steve220]

I will be. See the link in my signature for my build thread!

[jonny f]

I would recommend a 3.1

[Retroman]

I would stick with the 3.44, its a good all round diff for the road.

 

Surely the whole point of a blower is for acceleration and throttle response, and a 2.7 diff will destroy that.

 

They are an artificial economy device which destroys the fun of a Mini.

 

I would never entertain a 2.7 diff in any Mini they are pointless.

 

If you want a quiet economical bland motorway cruiser shopping car put a 2.7 diff in.

[nicklouse]

windy hill roads etc then a 3.44

 

long motorway drive a 2.7

 

same as any mini build really.

 

change the diff pin what ever.

[Northernpower]

I run a 3.1 with a cross pin in my na 7 port. It runs on 13 inch wheels and has 83lbs of torque at the wheels. As with all fd ratios it's a compromise. It's great on the open roads and third gives 95mph so that works well on the back roads but I find it's a little high for town driving so I tend to drop down to third. For my spec 30mph is right on the point of where it comes onto cam.

I've changed it from a 3.4 and would not go back but if I were to do it again I would consider a 3.2. If you're going to get significantly more torque from your blown set up I'd stick with the 3.1.

[Turbo Phil]

I think a lot of folk are missing the point here. A supercharged engine will make huge amounts of torque compared to a NA engine making it far easier to pull a taller final drive. When you have a possible 150ft/lb at your right foot I'd take advantage of that, why run a 3.44 ?

Phil.

[Northernpower]

I think a lot of folk are missing the point here. A supercharged engine will make huge amounts of torque compared to a NA engine making it far easier to pull a taller final drive. When you have a possible 150ft/lb at your right foot I'd take advantage of that, why run a 3.44 ?

Phil.

Totally agree.

[mini13]

As Phil says,

My advise would be a 3.1 with a straight cut box, (as the 2.5 first will get pretty tall if you go higher) or a 2.7 or 2.9 if it's a helical box.

[nicklouse]

 

I think a lot of folk are missing the point here. A supercharged engine will make huge amounts of torque compared to a NA engine making it far easier to pull a taller final drive. When you have a possible 150ft/lb at your right foot I'd take advantage of that, why run a 3.44 ?

Phil.

Totally agree.

 

but as he says

 

Forgot to mention.......95% of my driving is on open roads, 100kph zones.....I live out in the country. 

 

will he even get into 4th?

also note location. NZ

[Northernpower]

 

 

I think a lot of folk are missing the point here. A supercharged engine will make huge amounts of torque compared to a NA engine making it far easier to pull a taller final drive. When you have a possible 150ft/lb at your right foot I'd take advantage of that, why run a 3.44 ?

Phil.

Totally agree.

 

but as he says

 

Forgot to mention.......95% of my driving is on open roads, 100kph zones.....I live out in the country. 

 

will he even get into 4th?

also note location. NZ

 

He'll get into fourth if he drives fast enough , you could apply the same argument as to why the OP is adding a supercharger at all. If it's too low geared all it will do is spin the wheels. 

[Turbo Phil]

As he says 95% of his driving is on open 60mph roads I'd say a 3.1 would be ideal. The engine will easily pull it and it will help with economy a bit, supercharged engines being rather thirsty.

Phil.

[Chris.Williams]

Well, I’m thankful to all who had their input.... 3.1 could be a fine compromise between 3.4 & the leggy 2.7.
And I think Nick is correct, diff should be done.
While I have everyone’s attention, thoughts on Aldon Amethyst?