Diff

General E30 related discussions -
Please put technical questions in E30 Tech Help forum below

Moderator: martauto

Post Reply
User avatar
Siggo
E30 Zone Newbie
E30 Zone Newbie
Posts: 123
Joined: Sat Sep 29, 2012 11:00 pm

Thu Jun 22, 2017 6:22 pm

Hi
I have looked at past posts. I have a 391 lsd and was thinking of trying it in my e30 s50 . Would it be worth it or would 2 gear be like 1st so on think I have 364 at the minute and had it on rolling rd 279 bhp topped out 133 mph any one tried this many thanks
Tedswagon
E30 Zone Addict
E30 Zone Addict
Posts: 2195
Joined: Sun Nov 23, 2008 11:00 pm
Location: Edinburgh

Thu Jun 22, 2017 11:40 pm

I'd an uprated Medium case LSD 3.45 ratio in my s50b30, with the 5 speed box in my old compact. It happily went to 120 before the end of the straight at knockhill. Would have gone faster if the straight was longer, but would have been better if was quicker out of corners imo.

Not sure if that helps.
E30 316i auto coupe build thread here viewtopic.php?f=25&t=273035
User avatar
Brianmoooore
E30 Zone Team Member
E30 Zone Team Member
Posts: 49359
Joined: Mon Jan 10, 2005 11:00 pm

Fri Jun 23, 2017 11:50 am

What's first gear like at the moment? Fully usable or unsticks the tyres at the slightest press of the throttle?
The diff. change is between 7% and 8%, whereas the change from 1st to 2nd gear is over 40%, so it's not going to change 2nd to another 1st.
User avatar
Siggo
E30 Zone Newbie
E30 Zone Newbie
Posts: 123
Joined: Sat Sep 29, 2012 11:00 pm

Fri Jun 23, 2017 4:35 pm

Not bad really car grips very well . Just have it sitting here thought il throw it in see what's it's like. Just worried first gear would be useless
User avatar
Siggo
E30 Zone Newbie
E30 Zone Newbie
Posts: 123
Joined: Sat Sep 29, 2012 11:00 pm

Fri Jun 23, 2017 6:45 pm

Riding on 17 inch wheels
User avatar
Siggo
E30 Zone Newbie
E30 Zone Newbie
Posts: 123
Joined: Sat Sep 29, 2012 11:00 pm

Thu Jun 29, 2017 4:15 pm

Just cleaned tag on diff it's a 338v5472 so it's not on e30 chart
User avatar
Siggo
E30 Zone Newbie
E30 Zone Newbie
Posts: 123
Joined: Sat Sep 29, 2012 11:00 pm

Sat Jul 01, 2017 12:44 pm

Right got every thing ready to have a go doing it my self but it seem that the diff that's in is smaller in length
Than the 391 lsd about 1 inch so can I somehow shorten the prop to make it fit or need a prop as well know cheers
User avatar
Brianmoooore
E30 Zone Team Member
E30 Zone Team Member
Posts: 49359
Joined: Mon Jan 10, 2005 11:00 pm

Sat Jul 01, 2017 2:32 pm

E30 prop has a sliding section on the rear section. Clamp nut is just behind the centre bearing.
Looks like this might be a small case diff. though, which might not take kindly to the torque from a S50 donk.
How many bolts hold the rear cover in place?
User avatar
Siggo
E30 Zone Newbie
E30 Zone Newbie
Posts: 123
Joined: Sat Sep 29, 2012 11:00 pm

Sat Jul 01, 2017 3:18 pm

8 the one in now has 6 bolts tar
User avatar
Siggo
E30 Zone Newbie
E30 Zone Newbie
Posts: 123
Joined: Sat Sep 29, 2012 11:00 pm

Sat Jul 01, 2017 8:26 pm

Seen on the wiki page yep have a medium case diff 8 bolts was told out of e30 325 sport 391 lsd . One that in is a 338 6 bolts think out of e36. Which is ok handles the power. It has e36 gearbox 2.8 . Wiki page saying can only move prop 10 m so if it still to short do a buy e36 prop cheers
Post Reply