E36 Rear Diff ratio

[muckles.19]

Does any one know the rear diff ratio of the BMW E36 325i ?
And what size wheels were standard?
What revs does it pull in 5th at 70MPH?

regards
Mike

[ac]

Re: E36 Rear Diff ratio

This may not help,My Sportster is runing with a 3.25 lsd from an E30 model and a 325i M50 from an E36 model.
In 4th gear at 70mph it's 3500 rpm
In 5th gear at 70mph it's 3000 rpm
I changed to this ratio earlier this summer because the previous diff was over 4000rpm to get to 70mph making 1st and 2nd almost redundant !
Regards Andrew

[muckles.19]

Re: E36 Rear Diff ratio

Hi Andrew

Do you know what the diff ratio is that you have now, and what size tyres you are running?
I am building a Cabrio, and will use a Sierra diff, and need t pick one as close as possible to suit the car, or vary the tyre ratio slightly to achieve the optimum mph/1000revs.
regards
Mike

[muckles.19]

Re: E36 Rear Diff ratio

Hi Andrew again!
I've re - read your reply and realised your diff is a 3.25 diff: I originally read it as though it was from a 325!
Sorry.
What tyres are you running to achieve 70mph at 3,000rpm
Mike

[ac]

Re: E36 Rear Diff ratio

Hi Mike
Sorry forgot the tyre bit, The tyres are Falken FK425 size 225/50 zr 16" [rolling rad 202cm]

[teazle]

Re: E36 Rear Diff ratio

Hi Mike,
As you know you will have same set up as me and I recently changed my Sierra 3.62 diff for 3.38 ; not that much difference between the two, 250 rpm (at)70 mph, now running much the same as Andrews (2950 (at) 70)but better pull in 2rd (at) 3rd. The engine could cope with a 3.14 ,if you can find one,but that depends on what you want from the beast!To be really picky my engine still sounds a wee bit over reeved but may not when I quieten her down. How did you get on with loom wiring, hope my e-mail helped... Ihave 2-3 diff contacts if you need a source and I have a 3.62 going cheap..
All the best
Chris C (tyres are GY eagle F1 205/55 ZR 16)

[Patrick]

Re: E36 Rear Diff ratio

This should help with calculating diff ratio's:

http://www.geocities.com/z_design_studio/

Patrick
www.msportster.co.uk