On a 1993 525i 5speed:

1) What is the stock (open) differential?

2) What is the best/most common LSD swap that won't kill fuel economy too terribly much (don't need to switch ratio's, just want both wheels pushing)

3) From which car does that ideal LSD come, and where should I be looking to purchase one?

Thanks guys!

-Evan

http://bmwe34.net/e34main/upgrade/Recipe.htm :alright

http://bmwe34.net/e34main/upgrade/Recipe.htm :alright

So it looks like my best bet is the 3.46 LSD that comes stock in the 535im - where would be my best chance of getting one?

-Evan

The 535 came with an open 3.46.

The 535 came with an open 3.46.

yes, but I've heard reports of some having the LSD. Can't confirm it, though, both of mine have the 3.46 open diff.

I recommend the 3.73 LSD, more off the line, and not a big dip in speed/RPM and fuel economy.

The 535 came with an open 3.46.

Mine has 3.46 LSD.

Mine has 3.46 LSD.

Those things are impossible to find, I ended up buying a 3.73LS for my 535i. I actually like the stock 3.46 ratio. Any interest in trading since you are going to a M5 engine?

Some of the 535/5spd cars definitely had LSDs from factory. The one that I got all the drive line stuff outta for the turbo project had one.

I swapped in a 3.46LSD out of a 535. I don't think I would want any lower gear because cruising down the interstate the engine is revs are getting up there. I started with the 4.10(stock auto) rear, but 1st was useless. A 3.30-3.40:1 would be ideal.

i thought i read somewhere that in the early years of the 535iM they all came with the 3.46LSD, then later BMW changed it to an open diff (why would they do that I ask?). Has anyone else heard this or am I sadly mistaken?

i thought i read somewhere that in the early years of the 535iM they all came with the 3.46LSD, then later BMW changed it to an open diff (why would they do that I ask?). Has anyone else heard this or am I sadly mistaken?

They got the open diff when traction control came out. I think the traction control cars could still get an LSD with winter package, but don't quote me on that.

The 535 came with an open 3.46.

I got a factory 3.46lsd ... the other 535im we had also had it. :alright

On a 1993 525i 5speed:

1) What is the stock (open) differential? -Evan 3.23 though I have heard of some having a 2.91. check your tag on the diff.



2) What is the best/most common LSD swap that won't kill fuel economy too terribly much (don't need to switch ratio's, just want both wheels pushing)
-Evan 3.23 LSD

3) From which car does that ideal LSD come, and where should I be looking to purchase one?

Thanks guys!

-Evan

dunno mine's from another `92. Xmon might know if that car was a cold weather package. my car had a 4.10 LSD and cold weather package

I have a 391 limited slip in my 89 535i parts car. Anyone want it? Make me an offer.

I have a 391 limited slip in my 89 535i parts car. Anyone want it? Make me an offer.

pm sent

There is no way I have a 3.23 in my 95 525i. I am at 3k going 70 in 5th.

There is no way I have a 3.23 in my 95 525i. I am at 3k going 70 in 5th.
what do you mean? Cause that sounds about right to me.

what do you mean? Cause that sounds about right to me.

I've got a 3.64 in my autobox car, I'm at 3k at 80. Unless the final drive is that far off between the two, he should be at MUCH lower rpm.

it is that far off... and your 5th gear isn't 1:1

m50 autos have od and 4.10s

535s autos and manuals have OD and mid 3's

m50s MANUALS do NOT have od 5th (1:1) and run a 3.23 rear gear.

There is no way I have a 3.23 in my 95 525i. I am at 3k going 70 in 5th.
That is exactly right. (And no, I am not just randomly saying that, I actually went ahead and punched all the ratios and tire sizes into a gearing calculator).

I've got a 3.64 in my autobox car, I'm at 3k at 80. Unless the final drive is that far off between the two, he should be at MUCH lower rpm.

Wha?

I've got a 3.91 on my 535 auto and I'm at 3k for 80 mph...how is that possible?

My 89 535i manual also has 3.46 LSD. I recently converted my 95 525iT to manual and installed 3.23 LSD. I would not want to use a numerically higher ratio such as 3.46 in this car. It is a daily driver that sees regular highway use at 70-80 mph. If it was used more for short local trips and sport driving such as autocross, then the 3.46 would make more sense to me.

Interesting stuff, I bought a parts car, a '90 535im and it came with a 3.64 LSD, thought that was stock. My car came with a 4.10, but I didn't like it, now I run a 3.91. but the 525 is different I guess