High lock diffs

[Jean]

Sure. So you'll have a 75% lock diff?

I believe so, Wanganstyle is building it and I am going to 3.46 from my 3.64 to get slighly more out of 2nd gear.

[shiboujin]

Where do you know this from? I have a 4 disc in my car, no machining required. You can drive it if you are local

Because there physically isn't enough space for 4 clutches... The beville washers would be completely compressed at that point. Your preload would be insane. You can run 3 clutches if you remove the 4mm spacers (letting you add 1 clutch and 1 dogear plate). Where do you get the space to add a 4th set?

[Wanganstyle]

I didn't have to think of anything special, no machining required.

Big diff houses make billet end caps for a reason, the stock units are powered metal and really not the greatest cut down in strength.

Don't machine the cap; $0 cost is good. more strength is also good;

I'd rather have a stout un-altered construction and structural integrity than more "lock up". Skilled drivers can high speed drift open diffs on track!!!


If you drive my e30 4 disc you won't feel any garbage noise of a welded doing u turns. My e30 is a street car, it got a street diff.

There are a 3 different ways to do a 4 disc without machining anything.

If stacked right, preloaded or unloaded the stock un-modified LSD center capsule can take over 1krwhp shockloads with high locking configurations and not suffer structural breakdown. Machining the cap on 2.79-3.07 geometry caps is really not possible IMO due to the design of casting, so my 2.93 could not go 4 clutch via machining.

The high ratio cap is 7m thinner and would allow quite some space for discs but the position of spider would need to be adjusted quite some. Not saying a high ratio capsule cap cannot go on a low ratio capsule to create a large cavity for even more clutches, but at that point billet end cap is really needed.

That would be the Oem way to fit 6-7 clutches in a Oem LSD case. Billet end cap+ low ratio capsule+custom ring gear spacer if needed for 3.15-4.45 ratios.

BMW/ZF did the thinking; I just stumbled upon this a few years ago and have been reconfiguring variations on the factory setup.


ZF Bmw Oem 4 clutch LSD.
188mm unit.

The rosetta stone Center stack;

100% Oem bmw unit. 4 clutch discs and 4 dog ear plates. All 2.0mm bmw spec thickness.

[Ian Bowers]

YUPS. my E30 does a throttle induced doughnut or 2 every time I need to change directions on my street now........addicting.....

No comment, but my DZ101 Star Specs that were new in may sure look old.

[Wanganstyle]

No comment, but my DZ101 Star Specs that were new in may sure look old.

Somebody is addicted to drifting.....
:D

[Wanganstyle]

BMW OEM asymmetric center housing. Extra oiling groove as well.



This is the legend of oem un-obtainium; asymmetric center section+ 4 clutch disc LSD. Oem bmw stuff!!

[Jean]

See you tomorrow man!

[shiboujin]

I didn't have to think of anything special, no machining required.

Big diff houses make billet end caps for a reason, the stock units are powered metal and really not the greatest cut down in strength.

Don't machine the cap; $0 cost is good. more strength is also good;

I'd rather have a stout un-altered construction and structural integrity than more "lock up". Skilled drivers can high speed drift open diffs on track!!!


If you drive my e30 4 disc you won't feel any garbage noise of a welded doing u turns. My e30 is a street car, it got a street diff.

There are a 3 different ways to do a 4 disc without machining anything.

If stacked right, preloaded or unloaded the stock un-modified LSD center capsule can take over 1krwhp shockloads with high locking configurations and not suffer structural breakdown. Machining the cap on 2.79-3.07 geometry caps is really not possible due to the design of casting, so my 2.93 could not go 4 clutch via machining.

The high ratio cap is 7m thinner and would allow quite some space for discs but the position of spider would need to be adjusted quite some. Not saying a high ratio capsule cap cannot go on a low ratio capsule to create a large cavity for even more clutches, but at that point billet end cap is really needed.

That would be the Oem way to fit 6-7 clutches in a Oem LSD case. Billet end cap+ low ratio capsule+custom ring gear spacer if needed for 3.15-4.45 ratios.

BMW/ZF did the thinking; I just stumbled upon this a few years ago and have been reconfiguring variations on the factory setup.


ZF Bmw Oem 4 clutch LSD.
188mm unit.

The rosetta stone Center stack;

100% Oem bmw unit. 4 clutch discs and 4 dog ear plates. All 2.0mm bmw spec thickness.

You're saying a lot of things with little to no back up. I have a 2.93 amd machined the cap down 4mm and there's plenty of space/material left for structure. higher ratio caps aren't smaller, they simply move the cap to capsule mounting point farther in or out. All capsules that I've measured are the same between 2.93/3.73 (188 medicum case lsds).

That still doesn't explain how you fit 4 clutches into an unmodified cas/capsule/cap.

[Wanganstyle]

You're saying a lot of things with little to no back up. I have a 2.93 amd machined the cap down 4mm and there's plenty of space/material left for structure. higher ratio caps aren't smaller, they simply move the cap to capsule mounting point farther in or out. All capsules that I've measured are the same between 2.93/3.73 (188 medicum case lsds).

That still doesn't explain how you fit 4 clutches into an unmodified cas/capsule/cap.

2.93 cap really can't take 4mm removal and be strong. Have fun w your weak cap. I proposed this and my machine shop turned down the work... And then fitted the thin cap to work in Low gear Capsule

My machine shop decided that dropping the bearing surface and re-cutting a circlip groove for side axel would be stronger, easier. So they have done it






I just posted a photo of bmw Oem 4 clutch disc LSD center. Did you not see?

I don't have to do anything. bmw makes the 188mm LSD in Oem 4 clutch disc.

[Wanganstyle]

Bmw Oem makes 4 clutch LSD for 188mm. How hard is that for you to understand?





You need to do more research and spend more time on this LSD subject if you really want to understand it.


Lsd end caps are different, capsules are different between high and low.

Low number capsule has more depth; oem stack for 2 clutch uses same center ramps and all other stuff in low and high ratio.


Here's the caps; left is From 3.64, right from 2.93. Notice the thickness difference that lives inside LSD case

[shiboujin]

2.93 cap really can't take 4mm removal and be strong. Have fun w your weak cap.


I just posted a photo of bmw Oem 4 clutch disc LSD center. Did you not see?

I don't have to do anything. bmw makes the 188mm LSD in Oem 4 clutch disc.

You posted a picture of a center stack. I could stack 20 clutches and take a picture. That doesn't prove it would fit in a stock capsule housing.

I've run 400whp through my "weak" cap with no problems.

What diffs came stock with a 4 clutch lsd? I've never heard of that.

Inside the center of the diff, you have a fixed amount of space. Stock, there is a 4mm spacer you can remove an add a 3rd clutch. That makes sense. But without a different top or machining out more space, how do you fit 4mm more?

I can see 4 clutches if some diffs came stock with 4 clutches but I've cracked open many stock diffs and never seen 4 clutches. Maybe E36 M3 diffs?

[shiboujin]

Bmw Oem makes 4 clutch LSD for 188mm. How hard is that for you to understand?

You need to do more research and spend more time on this LSD subject if you really want to understand it.


Lsd end caps are different, capsules are different between high and low.

Low number capsule has more depth; oem stack for 2 clutch uses same center ramps and all other stuff in low and high ratio.


Here's the caps; left is From 3.64, right from 2.93. Notice the thickness difference that lives inside LSD case

I've done research. Everything you post has no real proof behind it. Yea the two caps have different depths into the capsule. But both diffs that I've torn apart with those ratios have had exactly 2 clutches in them.

You still have not explained how you fit 4 clutches into a diff that came with 2 clutches. I have NEVER seen a stock diff with 4 clutches stock.

Edit: also, the difference between the low gear and high gear caps are more than just the insides, the bearing is pushed farther out on the higher gears so you can't use that one in a low gear capsule.

Edit edit: wanna just pm or email me? I don't think everyone else on this thread likes our derailment. I'm genuinely interested in what you know. Diff knowledge is few and far between. You are the only other person I know of that has legitimately modified a stock diff.

[Wanganstyle]

bmw lsd caps also have different thickness Oem.

these are both from 3.15-4.45 gearing lsd's. 1mm difference.




Some diffs have thick compression rings, some have thin. Some have 4mm bottom plate spacer Oem, some have thinner ones.

Several different setups. More than 1 here.

This is a bmw old school sideloader 188mm. Some have 75% locking 4 clutch disc low ramp angle lsd's from the factory.

If you can find one in very nice shape with 75% 4 disc I suggest you buy and tear it down. Won't be cheap!!

[shiboujin]

So this is what I'm getting from this:

E30 LSDs are all 2 clutch
Some other 188mm ZF diffs came with 4 clutches and "75%" lock.

Which leads me to 2 questions:
1) What cars did the 4 clutch diffs come in?
2) Define "75% lock"

[Wanganstyle]

So this is what I'm getting from this:

E30 LSDs are all 2 clutch
Some other 188mm ZF diffs came with 4 clutches and "75%" lock.

Which leads me to 2 questions:
1) What cars did the 4 clutch diffs come in?
2) Define "75% lock"

From historical viewpoint:

Some 188's came with:

25% lock 2 disc
40% lock 4 disc
75% lock 4 disc

I only car I know of that came consistently w 4 disc LSD is e9 Bavaria. 70's stuff.

I don't define lock; this is just bmw oem specs. My preference would be for a KAAZ 2 way like I used to have in my RX7. lock of those.....LOTS!!