Sport or M3 diff?

[turners]

I currently have a modified 2.7with a sports 3.91 diff. I have been advised that an e30 m3 diff will in fact work better. Is this true and how will each diff affect the way the car accelerates etc?

[maxfield]

it will slow the cars acceeleration down by a fair bit.

but will be more economical

altho the torque from the 2.7 should make up for it

maybe a 3.45 will be a better choice or even 3.64

[Andy335Touring]

I'd say you need a pre-face lift sport diff, 3.64

M3 diff would be too long geared, 3.25

[turners]

Will the 3.64 dif make also make it slower or would it not really make a difference? i have just got a bit obsessed with acceleration and dont want anything to hinder that.

[Templ8e30]

I've got a 2.7 with a 3.73 325i auto diff.

Acceleration is very good and no annoying revvyness at motorway speeds.

Cheers,

Iain T

[Brianmoooore]

3.25 is for use with a 1:1 5th gear box, not the more usual E30 overdrive top box.
3.64 would be about ideal I would think.

[gooner1]

So a 3.25 E30 m3 diff would be good in a m30 conversion along with an m3 prop ,yes.?

[Andy335Touring]

So a 3.25 E30 m3 diff would be good in a m30 conversion along with an m3 prop ,yes.?

No, a 3.64 or a 3.46(rare) is what you want unless you do plenty of motor way driving and want to keep the revs down ?

[gooner1]

http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... 19978&rd=1

Bugger, good job i didnt bid then. Thanks Andy, if anyones interested seller wants 32 euros to ship here.