High lock diffs

[shiboujin]

So you have one of the center sections from an e9 or similar in a regular E30 pumpkin?

IE you didn't take a stock E30 2 clutch diff and fit in 2 more clutches without modifications? If it is a stock E30 center section, what parts did you use to shove in 2 more clutches?

[Wanganstyle]

i've done research:

Not enough.


Everything you post has no real proof behind it;

you can disbelieve anything on the internet you like. Free usa :)


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.

****
there are more than 2 style of caps on bmw's you have seen on the road.

Try tearing apart +++ more diff's from all different era cars to figure it out.


The 4 clutch ones are rare, and not really supposed to happen- but they are fit oem by bmw into usa spec cars. You could call zf engineering and ask them as they make the diffs? I actually was not expecting them to possibly be 4 clutch from bmw; the 4 clutch units also have funky center sections; low locking U shaped symetric is spec'ed and also Asymetric in some.

the 75% locking is a center section with ramp angles decreased; this was also an OEM spec'ed unit.
****

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.
****
i'm sorry, but i have seen a bunch of 4 clutch lsd's stock, from bmw/zf production- all were factory items.



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.
*****

i posted photos of how a high ratio cap can have its bearing surface sunk and circlip relocated for low capsule use- did you see those above?


So you have one of the center sections from an e9 or similar in a regular e30 pumpkin?
****
no. That would cost more than a kaaz 2 way lsd complete. You can swap center ramp sections between 4 clutch and 2 clutch units to increase/decrease/change up lock style.

[shiboujin]

I agree with everything you're saying and I understand it. Your phrasing makes it sound like E30s came stock with 4 clutch lsds. From what I can tell from what you're saying, 4 clutch lsds (even parts for them) are hard to find and rare.

In my every day practicality, it doesn't seem feasible for any regular joe shmoe to do a non modded 4 clutch setup. Unless, do you have an easy way to get those pieces?

[The Humjet]

In my every day practicality, it doesn't seem feasible for any regular joe shmoe to do a non modded 4 clutch setup. Unless, do you have an easy way to get those pieces?

^^^Took the words out of my mouth Yoshi. Something I want to know for people like me who find it hard to grab hold of an LSD from where theyre from
Great thread you've got here, learnt a lot about LSD's by just reading this. Keeping comments rolling. I'll just read along and not ask any newbie questions. And leave the comments for you e30 brainiacs to write

[shiboujin]

I've never messed with 188 diffs from other cars. I only have experience with factory E30 LSDs and a few from similar cars (E28s mainly). The ramp angles have always been the same and most parts are as well. Unless the 4 clutch parts are easily attainable, my $75 machine job to shove in a 4th clutch seems to be the most viable/cheap option. I fail to see how it would make the top hat any weaker.

PS: It isn't that I'm not comprehending the concepts, it simply took me a while to get what exactly you were saying. EG I was talking E30 diffs in general while you were talking about 188 diffs in general.

[Wanganstyle]

Sorry I'm not as clear on some items as I could be; you however are very good at technical writing!!

No usa model e30 I know of has a 4 disc from bmw installed from the factory line. Perhaps a competition spec e30m Evo 2.5 with Motorsports options, but I'm sure that costs more than I can stomach. I'd rather pay for s54 parts!!! They cost less than anything EVO 2.5.

E36 m3 sedan and coupe; auto and manual have a 2 disc LSD stock. Revised casting high cavity late model case is the only real difference. Think my lsd thread has photos of the different cases

The 188 is bread and butter of zf; it's used in all the bmw's x 3 decades.

I have never touched a Porsche, alpha, Opel, Volvo variant of the zf188 as my supply chain is not setup for anything euro besides bmw. Out of affordability range for me to handle. If you come across a vendor who will bulk deal and you need someone else to buy one, I'd be interested. I just can't stomach 944 turbo price for a unit, or find the rare Volvo unit in my contacts, I have never seen an opel car stateside besides Cadillac catera and those are all open diff auto (I think, could be wrong)

There are many more Oem users of zf 188, if you have the resources you could dive deeper in and perhaps uncover better options from other sources? I think that alfa Romeo units are more than 2 disc, same for Opel?

[Wanganstyle]

^^^Took the words out of my mouth Yoshi. Something I want to know for people like me who find it hard to grab hold of an LSD from where theyre from
Great thread you've got here, learnt a lot about LSD's by just reading this. Keeping comments rolling. I'll just read along and not ask any newbie questions. And leave the comments for you e30 brainiacs to write

Yosh has much easier to follow intro to LSD info on his site :)

Regarding 4 clutch;

Not that easy to play stack stacking game unless you have many parts from the factory parts bin to combine.

If you had a bunch of different chassis LSD units at your disposal you would figure out some nice combo's naturally.

I stopped keeping diff tags after a while.....

Also the time and patience to deal w it; it's definitely do-able by a higher level diy guy though.

Securing all the parts required to puzzle this diff game out via OEM BMW parts bin could easily cost same $,$$$ as calling KAAZ USA and just ordering a top notch aftermarket unit. I may order one myself for my e36m hillclimb car, as I'm not sure an Oem DNA diff Size I want to run can handle the stresses I want to throw at it.




4 clutches is NOT STREET.

For Street and hpde cars don't really need more than stock reconfigure with 3 clutches to go "40%"

People needing even more lock are using R comps on track, drag/wangan racing with big power, drifting, etc. Car is not really a street car then, so diff setting is just that.

[shiboujin]

Lets do number figuring!

Kaaz 1.5 way is ~$1500

http://www.frsport.com/KAAZ-DBW3010-1-5-WAY-LSD-LIMITED-SLIP-DIFFERENTIAL-E30-325i-85-90_p_8565.html

Now lets say you buy a stock 3.73 LSD for $300 (about going rate right?)
The machining for my top hat was $75
The 2.1 dog ear plates I got for increased break away tq was $30 each ($120 for 4)
I got bimmer world ceramic clutch plates for $75 each ($300 for 4)

That's $795 total.

Now I'm not sure if the kaaz comes with new axle bearings or not but those were only like $30 each IIRC and require no real special tools/measuring tools to insert.

So that's a little less than half the price as the kaaz.

The 2.93 I had in my boosted car stood up to 95F days of full on drifting. It also only had 2 2.1mm plates and the other 2 were the stock 2mm. I could easily do U turns with my modified angle and only on hard accel will it kiiinda chirp tires. I recently disassembled it and everything was as if I had just put it in there. Unlike the original 2.93 that had a groove so deep into it that it almost had holes in it.

Also, since you are well versed in diffs (no sarcasm honestly), do you agree with my diagram of diff locking?


from: http://e30performance.info/viewtopic.php?f=22&t=1311

I've had people read it but most people don't know enough to agree/disagree. I would prefer to not spread misinformation.

[Jean]

Wanganstyle - it was nice to meet you today! Thanks for the diff, I picked up some GL5 non-synthetic fluid today on the way back (guy was saying it's not a good idea to use synthetic in a clutch style diff if it's not a DD - what are your thoughts on this?)

I'll post some pics up of the diff tomorrow when it goes back in the car, can't wait to drive it!

[Wanganstyle]

Wanganstyle - it was nice to meet you today! Thanks for the diff, I picked up some GL5 non-synthetic fluid today on the way back (guy was saying it's not a good idea to use synthetic in a clutch style diff if it's not a DD - what are your thoughts on this?)

I'll post some pics up of the diff tomorrow when it goes back in the car, can't wait to drive it!

yes, you should take a vid of your break in !!!!! hahahahahaha

Lets do number figuring!

Kaaz 1.5 way is ~$1500

Now lets say you buy a stock 3.73 LSD for $300 (about going rate right?)
The machining for my top hat was $75
The 2.1 dog ear plates I got for increased break away tq was $30 each ($120 for 4)
I got bimmer world ceramic clutch plates for $75 each ($300 for 4)

That's $795 total.

This should also include a modified center ramp section to have a 1.5 way style locking, so median guesstimate +~$100 for that work.

$800+center section mod + XX hours of yoshi labor? not including parts sourcing, etc?

I'd guess for the average person that it may take 20-30 hours the first time around to get a stable production system of machine work, find a vendor they like with the plates they want in stock, etc etc.

200% premium for a KAAZ 1.5way with 0 footwork time spent, 0 labor in teardown/clearnup/spec-ing/and assembly of LSD, 0 parts sourcing and the option to not have to find a LSD to begin with is very very very nice... also, its a BADASS product!!!



I've always ran non-synthetic fluid and locking diff additive, but that's my style - change fluid often, use inexpensive stuff. This idea is from the AE86 days- Fluid is a personal subject, so u can experiment!

Will check out locking diag-

KAAZ will live 1.5-2x the time of a Oem configure diff trying to be a KAAZ. Its also a much better designed unit; Cusco, OS Giken, others are also same as durability is concerned.

1990's design for a Japanese aftermarket diff

The BMW/porsche/opel/alfa/volvo zf diff design was commissioned by DR porsche in the 60's-70's?

The Materials used in oem bmw diff (steels, organic discs) cannot even compare to a KAAZ or os giken unit. I often find stock units with steel and clutch discs swapping material, IMO they can't take even stock engine stock power 100% stress for extended time.

I've gone to the extremes of stress of sheering all the inner teeth of my clutch plates so that they didn't even work...lol

this is one of my favorite photos of all time. Sheer tire smoking joy......



The TRD supra mk4 fitment LSD was under 1k dealer order. The cusco in my former rx7 was bought complete pumpkin w LSD inexpensively, the TOMEI unit in former ae86 was bought from KAAZ USA in socal for under 1k (KAAZ makes tomei lsd's). Another ae86 had a trd 1.5'street unit with trd 4.78 final drive; that setup was heaven.


No install labor for an Japanese aftermarket LSD besides installing bearings needed; playing the Oem bmw LSD game requires you to actually understand it and have the parts for it!!


The top end Japanese diffs are also more consistent at track, I have ran modified stock diffs in various forms at the same tracks (Laguna, buttonwillow, thunder hill). Street and 60 treadwear dot-r's. Compared to using a KAAZ or Cusco or TRD/Os giken unit, the lock up is more predictable with aftermarket unit. Of course the cost is 200% or more premium. To each their own...

With high grip tires chasing lap times almost all would prefer the aftermarket Japanese unit.....if in the budget.


That is my own opinion from having used a bunch of high end aftermarket units (Japanese on Japanese cars). Practicality is another story, install/sourcing price can range huge as it's aftermarket item.

For short/medium term gains the modified stock units work very well, nobody will dispel the gains over stock used 20-30year ++ worn 2 disc items!!

Honesty a brand new spec re-stacked 2 clutch oem LSD works pretty well as is. Most people can just stop there or add 1 more to be 3 disc.


it's not only lock that is concern- more of modulation after a half hour+ lap battle session. The organic plates and stock steels are not the best heat handling.......smear steel into clutch plate while drifting while tracking is my fav!!!!

[shiboujin]

The problem is, no one has been able to tell me what the specs for the E30 kaaz are. I've personally installed a 2 way into an S14 from kaaz and the quality was great. It drifted great too. But I never did find what the ramp angles were or any other specs about it. The stock E30 45 degrees is actually very aggressive IMO for a stock unit.

Once the diff is out of the car, disassembly and messing with the unit itself takes less than an hour. I'm pretty confident that my $800 modified stock unit is almost as good as a kaaz unit.

The bimmer world clutches (http://store.bimmerworld.com/motorsp...ches-p584.aspx) are much better than the stock material and should hold up to quite a bit of punishment. Plus with the 4 clutches spreading out the wear, things should last much longer through a track day.

Granted, my testing is only me, but I am sliding with 400whp in 95F weather for a few hours at a time. I think I put the diff through a decent stress test.

[u3b3rg33k]

...I picked up some GL5 non-synthetic fluid today on the way back (guy was saying it's not a good idea to use synthetic in a clutch style diff if it's not a DD - what are your thoughts on this?)

That's basically the same argument people make with motorcycle oil and the dino/synth engine oil. If you use an oil intended for a limited slip diff, it doesn't matter if it's synthetic or not - it's still oil, and the synthetic is usually better at being oil than "regular" oil. I run synthetic in everything, my motorcycle (I use the stuff formulated for wet clutches), transmission and diff. Additive packages in oils matter if it's a race engine and you change it constantly (ie, redline race oils, IIRC they have less detergents, but are intended to be changed after every race).

This is where I would start looking:

http://www.redlineoil.com/Products.aspx?pcid=4

I run the 75W140 NS GL-5 Gear Oil, as I have a torsen and don't want/need the limited slip additives.

If I was running my clutch pack diff, I'd run one of their other offerings.

[guibo09]

This is where I would start looking:

http://www.redlineoil.com/Products.aspx?pcid=4

I run the 75W140 NS GL-5 Gear Oil, as I have a torsen and don't want/need the limited slip additives.

If I was running my clutch pack diff, I'd run one of their other offerings.

why are you running such a heavy weight? i thought the recommended weight was 75w90?

[Wanganstyle]

Bimmer world stated that their clutches are stock units; reference Bfc thread on this item.

[shiboujin]

link? That would make me angry as IIRC pelican sells replacements for $45 and not Bimmer world's $75.