e30 diff

[varun1794 0]

hey guys i just blew my diff on my e30 320i facelift witch has a m50b25 in it, wat do you guys reckon is my best coice for a diff ratio? im not sure what ratio my old one was and also i dont hav much more then 200 to spend on the diff so sadly i dont think a lsd would be a option either

if anyone has a suitable diff for sale plz contact me

[*Glenn* 854]

I have a 3.64:1 medium case for $250

[BM WORLD 1264]

which gearbox do you have.

if you are using a e30 type box getrag 240 or 260 then something like a 3.46 3.64 3.73 should be ok

if you are using a e36 gearbox getrag 250 or zf tyoe etc with the 1:1 top ratio then you want lower numbers like 3.15 3.23 3.46 etc

i would say your orginal e30 diff would be something like 4.1 or3.91 etc should have a tag on the back of the diff

i take it its a small case diff , the replacing it with another one the same size will be easy if you want to change it to amedium case diff which can handle the power better then you will need the medium case axles to match

go to here to work out how many revs at speed etc

http://members.dodo.com.au/~wawawa/revs.htm

select your gearbox and diff ratio etc

[_ethrty-Andy_ 2122]

sack/save up and get an LSD. an M50 in such a light car is lethal without one, especially given the way it is no doubt driven. noone puts an M50 in an E30 to drive like a nanna. if you cant afford to do a conversion properly, you shouldnt have done it in the first place

[varun1794 0]

sack/save up and get an LSD. an M50 in such a light car is lethal without one, especially given the way it is no doubt driven. noone puts an M50 in an E30 to drive like a nanna. if you cant afford to do a conversion properly, you shouldnt have done it in the first place

well considering iv blown my budget on the car and only just got everything running right i dont think its a good idea 2 pay 600 for a lsd if i just got offered a open for 250 aslkongas its in good condition

[varun1794 0]

which gearbox do you have.

if you are using a e30 type box getrag 240 or 260 then something like a 3.46 3.64 3.73 should be ok

if you are using a e36 gearbox getrag 250 or zf tyoe etc with the 1:1 top ratio then you want lower numbers like 3.15 3.23 3.46 etc

i would say your orginal e30 diff would be something like 4.1 or3.91 etc should have a tag on the back of the diff

i take it its a small case diff , the replacing it with another one the same size will be easy if you want to change it to amedium case diff which can handle the power better then you will need the medium case axles to match

go to here to work out how many revs at speed etc

http://members.dodo.com.au/~wawawa/revs.htm

select your gearbox and diff ratio etc

wow thanks that just made my life alot easier haha yea i think its a 3.91

[varun1794 0]

I have a 3.64:1 medium case for $250

do u know how many ks on it by any chance?

[varun1794 0]

if im correct a lower ratio would giv better top speed biut slower acceleration?

[_ethrty-Andy_ 2122]

if im correct a lower ratio would giv better top speed biut slower acceleration?

yup

[varun1794 0]

hmm i shopuld probably go for acceleration since im never gonna be hitting 200 kmph around here

[_ethrty-Andy_ 2122]

hmm i shopuld probably go for acceleration since im never gonna be hitting 200 kmph around here

i had a 3.67 (LSD) in my M52B28 E30. i would have gone for a 3.91 (i think? 3.9x anyways). you probably have something around there now so you might feel dissapointed with a taller one. though your fuel economy would increase

[varun1794 0]

lucky you iv always wanted a m52 haha

well im still kinda lost with the ratios a bit n hav no clue wats goin on with the small and medium case stuff so ill do a bit of reaserch n then read this post again haha might understand it better

thanks 4 the help everyone

[_ethrty-Andy_ 2122]

lucky you iv always wanted a m52 haha

well im still kinda lost with the ratios a bit n hav no clue wats goin on with the small and medium case stuff so ill do a bit of reaserch n then read this post again haha might understand it better

thanks 4 the help everyone

lots of people tell you that the medium and small case diffs arent interchangable, however i went from a small case to a medium case when i still had my M20 and didnt have to swap axels or driveshafts etc. aparently im the only one that didnt have to change them, not sure why.

mind you i used E30 parts, and E30 medium cases might be hard to find and people use E34/E28 medium cases? dunno

[BM WORLD 1264]

choose the revs you are happy with at say 100km/h

anything other 2800rpm is getting pretty buzzy .

if you want a race car then 3500rpm etc is ok

my 328i with 5spd 1:1 top does about 2650rpm at 100km/h

so which gearbox are you using??

[varun1794 0]

choose the revs you are happy with at say 100km/h

anything other 2800rpm is getting pretty buzzy .

if you want a race car then 3500rpm etc is ok

my 328i with 5spd 1:1 top does about 2650rpm at 100km/h

so which gearbox are you using??

hey mate im using a getrag 240

[BM WORLD 1264]

hey mate im using a getrag 240

ok so a

3.73 will give you 2600rpm at 100km/h

or 3.64 2550rpm 100k's

3.91 2750rpm at 100k's

[varun1794 0]

ok so a

3.73 will give you 2600rpm at 100km/h

or 3.64 2550rpm 100k's

3.91 2750rpm at 100k's

will it be a big sacrifise on accelerration say fom a 3.91 to a 3.64

[hotwire 352]

Bugger all, work it out from the numbers:-

[slowe30 0]

when i swapped from a small to medium case, it bolted straight in, was quite easy really.

and you will feal the differance between those ratios, not sure how much but you will

if i were you i would leave the car off the road for a couple weeks and save up for an lsd

i used to swap from 4.1 to a 4.45 when i had my 1.8 engine and that was a noticable change, now im running a 3.25 lsd with the m52 and its WAY!!! to long for my liking