# E46 LSD options?



## bluskye (Jul 24, 2002)

Well, I helped my co-wroker with a 95 M3 LSD swap into his 98 323is. The swap took about 4 hours at a leisure pace, and surprisingly ... it went SMOOTH. During the test drive, i noticed that the open diff totally sucks, handling is now way superior to my e46 with the LSD allowing his car to hug corners without spinning out (that and the e36 is generally alot lighter). Not to shabby for a used $400 bmw lsd.

I saw at http://www.koalamotorsport.com, they are sellling a quaife e39 ATB Diffs and ATB conversion units (approx $600) to pop into your diff if you up to the challenge, which I am to save the $900+. Anyone know of any service, or even if Quaife will be developing an ATB kit for e46. I figured someone would be soon given that the e46 would surely get more volume for this type of thing.


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## mwette (Sep 16, 2002)

http://www.hioprace-tec.com sells one for E46 323/328


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## MicahO (Apr 19, 2004)

Sadly, the e36 case is different, and larger, than the e46 case. This means that the diffs used on e36's cannot be used on the e46 at all. I've done a lot of recent research in this area -

Brett Anderson (Koala Motorsport) will handbuild an e46 diff for you - if you've got your own case and are NOT changing the ratio, it will cost you $2650, give or take. It's a lot of work and he has to assemble the units in the box, so it's not something he advertises a lot. Changing ratios will increase your cost accordingly.

Diffsonline  (talk to Dan) will also build one for you. They use a Kaz LSD unit and build it into an e46 case. Due to the small size of the case and the size of the ring gears and LSD unit, the tallest gearing hey can build will a 3.15:1. On a 330 this is a nice gearing, though Dr. Phil here just went to an (open) 3.38 with some nice seat-of-the pants results. Putting in a 3.38 or 3.46 will be a nice boost for quickness, but will have the motor turning at highway speed, particularly on a 5 speed. With a change of ratio's, the pricing here will be about $2800. If you've already got a lower ratio rear to work with, you're looking at lower prices, somewhere in the $2K range.

Turner Motorosports also sells e46 LSDs as their racing diffs, pricing starts out around $4500.

I tend to think that if Quaife was going to make something available for the e46, they already would have done so - there's been a significant tuner market for these cars for quite some time, so no progess makes me think there will be NO availability in the future.

There really SHOULD be a factory LSD option in these cars.......



bluskye said:


> Well, I helped my co-wroker with a 95 M3 LSD swap into his 98 323is. The swap took about 4 hours at a leisure pace, and surprisingly ... it went SMOOTH. During the test drive, i noticed that the open diff totally sucks, handling is now way superior to my e46 with the LSD allowing his car to hug corners without spinning out (that and the e36 is generally alot lighter). Not to shabby for a used $400 bmw lsd.
> 
> I saw at http://www.koalamotorsport.com, they are sellling a quaife e39 ATB Diffs and ATB conversion units (approx $600) to pop into your diff if you up to the challenge, which I am to save the $900+. Anyone know of any service, or even if Quaife will be developing an ATB kit for e46. I figured someone would be soon given that the e46 would surely get more volume for this type of thing.


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## bluskye (Jul 24, 2002)

I saw that a guy on e46fanatics popped in a KAAZ LSD unit into his e46 323i using a used 328i auto diff (3.46 ratio!!):

http://forum.e46fanatics.com/showthread.php?t=159699&highlight=kaaz+diff

It leads me to think that the older e46's are using a casing like the e36s with enough room.

also http://www.performancegearing.com/ has e46 LSDs, but i have yet to contact them to see if they actually made a unit that i can put in myself, or if it's an entire Diff totally (the more expensive option).

So, if one day if someone makes a LSD unit i can put in myself, it would be much cheaper then buying a custom made unit, even if i have to stick with my current ratio which is fine.


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