M42club.com - Home of the BMW E30/E36 318i/iS

DISCUSSION => Engine + Driveline => Topic started by: thumper3ld on March 12, 2006, 09:47:45 AM

Title: LSD's
Post by: thumper3ld on March 12, 2006, 09:47:45 AM
Do medium and large case LSD's fit in our cars w/o modification. If not, what needs to be done to get them in?
Title: LSD's
Post by: kowalski on March 12, 2006, 07:22:18 PM
a medium does, i'm not sure about a large case, i think you need to change the CV's, but i could be wrong.
Title: LSD's
Post by: fabe on March 13, 2006, 11:47:18 PM
the big case can fit w/o any mod. swapped small diff to big diff before...
Title: LSD's
Post by: asubimmer on March 13, 2006, 11:49:04 PM
there are small, medium and large cases, the small and medium fit.
edit: fyi the one in the 318is is a small and 325's medium
Title: LSD's
Post by: fabe on March 13, 2006, 11:54:56 PM
and where did the 'large' case come from? is there one?
Title: LSD's
Post by: asubimmer on March 14, 2006, 12:07:16 AM
Quote from: fabe
and where did the 'large' case come from? is there one?
not from e30's...off hand I can't remember exactly what the larges came on.  But its not like it matters since they won't fit ;)
Title: LSD's
Post by: kowalski on March 14, 2006, 02:52:48 AM
Quote from: asubimmer
not from e30's...off hand I can't remember exactly what the larges came on.  But its not like it matters since they won't fit ;)


i believe it was the 7 and 5 serries that people use..

i know there is some people running arround with large cases... or im on crack... one of the 2:D
Title: LSD's
Post by: fabe on March 14, 2006, 04:36:26 AM
7 series? of cos that won't fit. btw, as far as I know the internals are the same for the bigger E30 casing and the rest of the BMW rear diff. I've swapped over carriers from E34 to experiment before.
And that the 520i rear diff is almost indentical with E30 big case rear diff except for the rear plate and the output flanges.
Title: LSD's
Post by: 2002maniac on March 15, 2006, 01:40:01 AM
Here we go.  4-cyl cars (minus M3) had a small case, 6-cyl cars had medium case, and V8 and V12 cars had the large case.

The medium case diff from an e30 will swap right in.  you dont need to change the flanges, axles, or anything.  They are quite a bit heavier though.
Title: LSD's
Post by: thumper3ld on March 28, 2006, 09:29:27 PM
Can an LSD from an e30 M3 be used on our cars with no modifications?
Title: LSD's
Post by: dude8383 on March 28, 2006, 10:45:10 PM
yeh im fairly certain of that.
Title: LSD's
Post by: 2002maniac on March 29, 2006, 12:53:28 AM
Quote from: thumper3ld
Can an LSD from an e30 M3 be used on our cars with no modifications?


yes.  It is heavier though.  Small case is plenty strong too.
Title: LSD's
Post by: thumper3ld on March 29, 2006, 05:29:19 AM
I was contemplating getting a 4.10 LSD from an e30 m3 to replace my open 4.10 diff. Think its worth it?
Title: LSD's
Post by: Zoso on March 29, 2006, 10:11:39 AM
I think it's worth it.  Unless you got a good deal on the E30 M3 LSD, I'd stick with the small case.
Title: LSD's
Post by: shellback on April 01, 2006, 07:15:08 PM
If I'm not concerned with highway engine noise, what diff do you recommend? Currently have a 4.10 lsd. Heard some talk about convertible lsd's or automatic cars with higher lsd ratios improving acceleration (that is - noticeable acceleration).
Thoughts?
Chris
Title: LSD's
Post by: ///Motorsport on April 01, 2006, 07:19:20 PM
http://www.diffsonline.com has some good new and used stuff as well as info/specs.
how hard is swapping diffs? i remember taking one bolt out for 325is suspension install to lower it, hopefully its all fairly simple.
Title: LSD's
Post by: e9nine on April 01, 2006, 07:20:03 PM
This is my next intended mod. A medium case 4.10lsd from a 325i or e30m3. I hate the lack of an LSD in tight auto-x turns :(
Title: LSD's
Post by: 2002maniac on April 02, 2006, 12:04:04 AM
Quote from: ///Motorsport
http://www.diffsonline.com has some good new and used stuff as well as info/specs.
how hard is swapping diffs? i remember taking one bolt out for 325is suspension install to lower it, hopefully its all fairly simple.


pretty easy.  it took me like 45min to swap mine.
Title: LSD's
Post by: shellback on April 02, 2006, 01:28:47 PM
so looks like 4.27 is the highest, correct?
Title: LSD's
Post by: e9nine on April 02, 2006, 03:58:23 PM
4.45 from a Ti. Good luck finding one though
Title: LSD's
Post by: Vladi on April 04, 2006, 03:12:59 AM
The 4.27 is the highest ratio on E30's. I just did a swap from 4.27 open diff to a 4.10 LSD. :D
Title: LSD's
Post by: M42boy on April 04, 2006, 11:28:09 AM
The 318i cabrios, for some reason, had 4.27 gears.  I think finding one with a LSD is hard to find.  I'm putting in a 4.10 LSD out of a 325i.  This is GREAT news that I don't have to swap out the flanges.  Someone told me I did.
Title: LSD's
Post by: e30_kid89 on April 08, 2006, 09:07:46 PM
is there any diff between the medium 325 4.10 lsd or the 318 4.10 lsd??? cuz i wanna either get another stock 4.10 LSD or swap in something better:D
Title: LSD's
Post by: kowalski on April 08, 2006, 09:26:04 PM
its not exactly better to swap in a medium case diff. it will weigh a little more and it will handle more power but unless your going to do extensive upgrades to your engine i.e. stroker, or turbo or somthing like that you wont need a medium case.
btw the 318 has a small case.
Title: LSD's
Post by: asubimmer on April 09, 2006, 01:33:02 AM
Quote from: e9nine
This is my next intended mod. A medium case 4.10lsd from a 325i or e30m3. I hate the lack of an LSD in tight auto-x turns :(
believe it or not an open diff is better for auto-x. for tight turns, I forget the radius, an open is better. BUT for like track and places w/ bigger turns than a parking lot, a LSD is better.
Title: LSD's
Post by: e9nine on April 09, 2006, 09:31:42 AM
Quote from: asubimmer
believe it or not an open diff is better for auto-x. for tight turns, I forget the radius, an open is better. BUT for like track and places w/ bigger turns than a parking lot, a LSD is better.


I beg to differ. My experience with auto-xing and open and limited slip cars proves the latter to be an advantage. 2 prevalent examples:
When steering with the throttle, you are able to get the rear-end to rotate better with an LSD.
Accelerating out of a tight turn with one tire spinning isn't sexy either :mad:
Title: LSD's
Post by: asubimmer on April 09, 2006, 12:39:33 PM
well you really don't want to be loosing traction in an auto-x, ie throttle steer or pegleg burnout, that is unless you aren't a mad JDM RHD D1 drifter yoooo
Title: LSD's
Post by: Gunni on April 09, 2006, 02:04:23 PM
I feel using a LSD to make angle adjustments of the car would make the main diffrence in a auto-x

there is nothing wrong with loosing traction slightly as it has benefits,
for instance you can accelarate more keeping the rpms higher and have the tires slipping slightly, as you are getting more power into the ground vs. full grip and lower rpmīs
Title: LSD's
Post by: e9nine on April 09, 2006, 02:44:37 PM
Quote from: asubimmer
well you really don't want to be loosing traction in an auto-x, ie throttle steer or pegleg burnout, that is unless you aren't a mad JDM RHD D1 drifter yoooo


I am not talking of that kind of traction loss (mad JDM bla bla bla). If you auto-x and have never lost traction before, or think traction loss is a bad thing...I guess we have very different styles of driving.

Picture the front of your car as an axis of rotation, sometimes you have to use perfect rear wheel slip to rotate you car. The front acts like a pivot and the rear rotates the car based on the drivers input. This is where the LSD shines in auto-x. Believe it or not, with the right set up there are a lot of times where your rear wheels will spin faster than the front either on purpose or not.

I guess we all have different driving styles but I will once again position steering with the throttle as being better than using the wheel especially for RWD cars (what i am used to)

Peg leg burnout, you'll never be effective in auto-x with that style of driving, you probably misunderstood what I said in the prior post.
Title: LSD's
Post by: asubimmer on April 09, 2006, 02:56:33 PM
ohh well, I suck at explaining stuff but who cares.  A little slipping is good like you said.  I thought you were talking more mad drifting stuff though.  I have always been told that the open will let you turn in a tighter radius b/c a LSD in a situation like that will spin due to the wheels being locked together.  again I suck at explaining things sometimes but I may be wrong.  Its just what I have been told forever.
Title: LSD's
Post by: Gunni on April 09, 2006, 04:55:40 PM
Quote from: asubimmer
 I have always been told that the open will let you turn in a tighter radius b/c a LSD in a situation like that will spin due to the wheels being locked together.


You are right, but this is true if you keep the gas full on,
but easing of it you adjust the thrust of the car and thus slip