LS Diff

[2ndBimmer]

I just noticed today at what a disadvantage I am with a very slippery rear diff (backing out in the snow :x ).

So it would seem a diff from a Z3 would be the best bet right? Where would be a good place to get one at? (Id be looking for OEM or something close, never a knock off)

[KIRASIR]

Any e30 differential, Mcoupe/Roadster, other Z3s differentials will all fit.
Some will require different halfshafts.

SL

[1996 328ti]

All these talkabout diffs. :(

I changed my diff fluid and the fluid was gray with metal filings.
Looks my LSD will be going very soon.

Now I need to decide what to do.

Some diffs will not fit because of the spare.

[2ndBimmer]

Well Ill have to wait until summer before I can afford anything, and there are several things Id like to do. Guess I have a few months to search for a differential.

[KIRASIR]

Personally, I think 325i e30 diff with the M cover is the best bang for the buck. (The spare has to be deflated)

SL

All these talkabout diffs. :(

I changed my diff fluid and the fluid was gray with metal filings.
Looks my LSD will be going very soon.

Now I need to decide what to do.

Some diffs will not fit because of the spare.

[ClubSport332ti]

Yeah, I did the e30, half shaft set up with a 3.46 diff. I will be selling diff and half shafts soon probably in the next month or so. But I agree tha t the z3 diff is a little pricey and the e30 is the best bang for the buck

[J!m]

My spare is taking up space in my garage...

[L84THSKY]

Please....someone educate me on the whole LSD issue and Diff sizes. What does having a LSD really do in terms of driving? Which diff will give me better acceleration in 1st gear? What are my options in the 318ti? What parts are required for each option?

Thanks
Eric



Yeah, I did the e30, half shaft set up with a 3.46 diff. I will be selling diff and half shafts soon probably in the next month or so. But I agree tha t the z3 diff is a little pricey and the e30 is the best bang for the buck

[nick_hegel]

Where is a good place to look for a lsd? Can anyone post a link or recommend someone??

[maurolin]

there is a local guy here that sells LSD's with a variety of ratios for $300
I am planning to get a 3.46 for my 3.2 engine.

[Constant]

Got mine from eBay, but also try http://www.theeurodepot.com/ for E30 stuff. I've been to the shop a few times, good people.

Constant

[ClubSport332ti]

Please....someone educate me on the whole LSD issue and Diff sizes. What does having a LSD really do in terms of driving? Which diff will give me better acceleration in 1st gear? What are my options in the 318ti? What parts are required for each option?

Thanks
Eric

Eric, look for a 3.73 Diff if you do a lot of highway speeds. If you want a great track car get a 4.10. You will need an Mcoupe dif cover to make it fit. Look on ebay for these LSD diffs. I sold one 2 months ago for $300

[ClubSport332ti]

http://forums.bimmerforums.com/forum/showthread.php?t=276648

[L84THSKY]

Here is what I really wanna know. Let's say I add all of my future upgrades; x-brace, fogged airbox, stromung exhuast, but I still want some more horsepowerr. I have a low mileage car (34K), so supercharging it is an option. I will be adding 17" wheels in the spring, and the diameter of the wheels are equal to stock (no RPM increase or decrease). What I want is more power in the low gears (acceleration) but no decrease in fuel economy. I also do not want to put a LSD in that increases my RPM's in 5th gear. I want to keep the RPM's equal or lower when I'm highway cruising. So if I keep standard size wheels, what combination of power increases(supercharging) boost acceleration, along with the proper size LSD will keep the car in low RPM's when cruising. Am I asking for the impossible? I don't like the idea of the car increasing in RPM's at highway speeds just to get a small boost in the low gears. My thinking(probably flawed) is that if I put in a supercharger, then I gain the low end, but I can put a LSD with a lower ratio to keep the RPM's down.

Here is a quote from the guy who did the LSD swap:

"The Poor Man's Supercharger
Swapping a 6-cylinder E30 rear differential to your 318ti"

"If you're one of the lucky few with a supercharger and would like to keep the rpms down while cruising, perhaps a 3.25 would suit your needs."

It seems that what he is saying is exactly what I want.


Eric, look for a 3.73 Diff if you do a lot of highway speeds. If you want a great track car get a 4.10. You will need an Mcoupe dif cover to make it fit. Look on ebay for these LSD diffs. I sold one 2 months ago for $300

[Constant]

What I want is more power in the low gears (acceleration) but no decrease in fuel economy. I also do not want to put a LSD in that increases my RPM's in 5th gear.

Hey, people actually read that LSD article? :wave:

This is a case where you can't have your cake & eat it too. At least not with the LSD alone. On the manual 318ti's, the gear ratio is 3.45. Here's a breakdown of the ratio swaps, if you don't change anything other than the diff:

> 3.45 = faster acceleration, higher rpms while cruising, ie 3.73 E30 LSD
< 3.45 = slower acceleration, lower rpms while cruising, ie 3.25 E28 LSD

You could offset the reduction in acceleration if you added a turbocharger or positive displacement supercharger. Turbos in particular love the increased load given by a higher ratio diff (smaller numerically). Just don't go too wild on the ratio, or you'll end up with not much improvement over stock. IMHO if I had a DASC, I don't think I'd stray far from 3.45.

Constant