Author Topic: Anyone using a 3.91 (or even 3.64) lsd? (Read 3227 times)

Bmw02er · « **on:** May 02, 2009, 02:00:36 PM »

I can get a 3.91 lsd and would like to know if someone is running one. If so, does it have a negative effect on the power curve during shifts? Does it feel different?
TIA!

tjts1 · « **Reply #1 on:** May 02, 2009, 04:15:25 PM »

I have a 3.64. Made the car quicker, quieter and easier to drive in the real world. 3.91, 3.73 and 3.64 are all good choices for the E30/M42.
http://www.m42club.com/forums/showpost.php?p=26477&postcount=28

Bmw02er · « **Reply #2 on:** May 03, 2009, 05:51:31 AM »

Thanks for the graphs. I will get the 3.91 lsd. Jsut a little lower revving at cruising but still sporty enough for acceleration. As I recall the e21 320is also used a 5-speed od coupled with a 3.91.

1991 E30 M42 · « **Reply #3 on:** May 03, 2009, 11:25:04 AM »

i have a 3.91 in one car and a 3.73 in another

DesktopDave · « **Reply #4 on:** May 04, 2009, 08:36:07 PM »

I'm going to swap in a 3.64 LSD this weekend. I'll let you know how it goes.

Bmw02er · « **Reply #5 on:** May 07, 2009, 05:55:36 AM »

Quote from: DesktopDave;71357

I'm going to swap in a 3.64 LSD this weekend. I'll let you know how it goes.

Yes please do. Curious!

Quote from: 1991 E30 M42;71281

i have a 3.91 in one car and a 3.73 in another

So how does that work for you?

DesktopDave · « **Reply #6 on:** May 08, 2009, 10:31:46 PM »

Here's an update - got an early start on removing the diff. Pulled half-shafts, loosened rear mount bolt. Then I came to the 19mm bolts that hold the diff in. Couldn't find my trusty 19mm wrench (spanner). While struggling/thinking/jerry-rigging, I dropped the end of half-shaft on my thumb. Wouldn't have hurt so much if I'd dropped the exhaust instead of shoving it off to the side. I'd advise everyone to do that. Heard fatherly advice: "Pain is the price of stupidity." Will try again tomorrow if the rain lets up.