Which Diff for a M30 3.5 ?

[Rich25i]

Hello just getting the bits sorted for my engine conversion and just wondering What diff i need. Do i use The 2.5 on my car or do i use the 3.5 diff?

Thanks

[bigdek]

Most peeps use a 3.64 lsd m8.

If you can lay ur hands on a 3.46 that would be best IMO as that is the same as an e34 535 .

These are rare though.

I have just found one for myself and is going on my tourer

[Rich25i]

Thanks for the reply so its best to use the standard E34 diff. I have a complete car with a nackared auto box but got a manual box off a friend.Do i use the E30 driveshafts with this or the E34 ones? I assume the E34 are longer?

Thanks

Need a little help with the drive train.

Also does the sport 535i have a LSD as standard?

[bigdek]

e34 diff won't fit as far as i know m8

[pacerpete]

E34 diff will not fit. An e30 M3 diff 3.25 ratio is a good motorway diff very long legged and because of the torque will not hinder your acceleration too much. 3.64 is a good allrounder , 3.45 is probably the best compromise but very rare, fitted to some alpinas and some e28s.
I have a good 3.25 and 3.64 diff available.

[Rich25i]

Thanks for your help. I might be intrested in the diff

Again thank you

[marakka]

To get a driveshaft to work you'll have to frankenstein one. Use the rear of one and the front of another. I do believe the diesel drive shafts will brdge the gap from the m30 tranny to the rear diff perfectly.

As far as what diff to use..... what do you plan on doing? Here in Germany m30's look for 2.91, 2.73 or 2.71 diffs. Anything over 3.25 is too steep here as there isn't much use for low end as the car is fast as is with the big six in there. The guy who supplies me parts has a 91 iS with m30 swap and he's running a 2.91 now and looking for a 2.71 if that gives you any ideas.

[Gussy]

Hey guys.
I have an M30 conversion myself for my E30. Should get around to fitting it the new year.
I would only be driving it the weekends so a long motorway cruiser diff isnt necessary.
I have a 3.64 already but for maximum grunt would a 3.91 be ok?
Probably get wheelspin everywhere would i and render 1st gear obsolete?!?

[colix]

me I use 3,91 but it is far too short for a road use...
anyway if you don't have problems to "cruise" at 4000rpm at 120km/h, use one because acceleration is really incredible...

[colix]

1st gear is obsolete in hard driving conditions with 3,91 and it is better for me...

[Andy335Touring]

I started off with a 3.25 dif, 1, 2, 3 gears were nice but 4th an 5th were a bit to long. A good dif ratio if you do quite a few of motor way trips.

I have a 3.64 at the mo and find it a little short geared, more so in 1st and 2nd gear. Most of the time i pull off in 2nd.

3.46 is a very good all round ratio.

I eventually want 3.46 dif with an M30 gear box fitted with the gears from an 325 Sport box as i'd like a nice long 1st and 2nd gear and slightly longer 3rd.

[colix]

andy, is there a conversion possible to have the gears of a m20 sportgearbox?

off course the m20 sportgearbox is the best for me,1rst gear longer is better

[Andy335Touring]

andy, is there a conversion possible to have the gears of a m20 sportgearbox?

off course the m20 sportgearbox is the best for me,1rst gear longer is better

I'm not 100% sure on this yet but the M20 box is supposed to be virtually the same as the M30 box, slightly differant casing around the bell housing and the M30 has some cooling fins on it that the M20 box doesn't.

Some one is looking in to stripping both box's and rebuilding the m30 one with the Sports ratio's, as soon as i know for sure i will try to post on here.

[Batch]

I have a 3.64 diff from e28 535, still haven't fitted it. I suppose it should bolt straight on, only the back end should be replaced (from e30 diffs) to sort out the rear hanger.
According to the e30.de the 3.64 is the best compromise between acceleration and cruising.

[Toby_Unna]

I have a 3.64 diff from e28 535, still haven't fitted it. I suppose it should bolt straight on, only the back end should be replaced (from e30 diffs) to sort out the rear hanger.

that sounds all wrong

the 2 e28 535/m535s i've had had a much longer diff than that, more like 3.07 (1 manual, 1 auto)

and no it won't go on an e30. it's larger than the e30 large case diff and you cannot swap drivecups or backplate unless you have them custom made.

Marakka - which diesel driveshaft fits?

i doubt if any will fit in p3, in this position the gearbox is further back than in any production e30. an e30 m3 shaft will fit without mods in p2 and p2.5 though (I have custom mounts)

[Wilson325i]

i have a S3.07 lsd

any 3.5 takers???

[Toby_Unna]

what case size, e30 large case?

[e30_Turbo]

Toby, a bit off topic, but I'm seriously interested in that 3.64 lsd you have, will catch you on msnm later dude

[Batch]

I have a 3.64 diff from e28 535, still haven't fitted it. I suppose it should bolt straight on, only the back end should be replaced (from e30 diffs) to sort out the rear hanger.

that sounds all wrong

the 2 e28 535/m535s i've had had a much longer diff than that, more like 3.07 (1 manual, 1 auto)

and no it won't go on an e30. it's larger than the e30 large case diff and you cannot swap drivecups or backplate unless you have them custom made.

Marakka - which diesel driveshaft fits?

i doubt if any will fit in p3, in this position the gearbox is further back than in any production e30. an e30 m3 shaft will fit without mods in p2 and p2.5 though (I have custom mounts)

hmmm, may be, will see if I have the rite diff

[pete1979]

i need a lsd for a turbo transplant that ant might be doin lol if any one has one let me know if not what else fits???

[dips346]

what would a 4:1 lsd be like on 3.5
thanks

[bigdek]

useless i believe