MFactory Mechanical LSD Diff - My feedback and request for opinions

[tradzilla]

Hi Guys

I have 325i 5 speed currently running a metal plate type mechanical LSD from MFactory (not helical) Running Bilstein & H&R shocks and springs and H&R Swaybars

When the diff was initially installed it was extremely loud, clunky and tight. there was no progression at all in the locking, it was on or off. It functioned essentially like a locking diff. You could almost describe it as violent. My major issue with this was midway through a corner, while going on and off throttle, you can feel the car trying to plough forward as the diff would lock engage. Great for hooning around and doing burnouts but not good for cornering.

Spoke to the diff place and they said it would loosen up, keep driving and see how it goes.

It didn't get any better

Spoke to M Factory and they advised the diff comes with a medium amount of pre load from factory, so take out some pre load and see how you go

Took it back to the diff place, told them to take down the preload to the lowest level possible.

It improved maybe 25 to 30%

Still now, accelerating in a corner changes the characteristics of the car mid corner, it wants to understeer and plough forward, when I lay off it neutralizes and abruptly changes the balance of the front end. Very unsteady and not predictable at all. The diff guys have suggested a loosening agent to help loosen up the clutch packs in the diff but im looking at other options now

QUESTION

Has anyone had this experience with this diff or any other mechanical type LSD Diffs and what was the remedy?

Im looking into the MFACTORY or Wavetrac Helical Diffs now, has anyone driven these types of diffs and can advise how they are through corners and how they felt the progression to full lock was ?

Thanks in advance

[bmwman91]

I had a Wavetrac unit built by member Wanganstyle on here. The Wavetrac unit was built into a Z3 medium case housing since it is stronger and lighter than the E30 ones. It is one of the single best upgrades I have ever made to the car. Everything is improved, more predictable and stable: acceleration, cornering and hard braking. It does make some loud clunking noises when switching between reverse and forward gears as the locking mechanism changes bias, but I could not care less about that. Wavetrac is also the way to go since it does not have the issue that Quaife and Torsen ones have wherein if one wheel loses ALL traction, all torque goes out that wheel. IIRC Wavetrac was founded by ex-Quaife engineers after some patents expired, and it's basically a Quaife with a lock-up mechanism that kicks in if you lift a wheel or hit ice...no more minimum traction requirement. In those situations with a Wavetrac, you can expect a little bit of scary-sounding clunking from the rear lol. At least I think it was the diff making the noises...I don't get into that situation very often.

Downsides...burnouts are hard or even impossible (granted, it is only a 200HP 2.1L M42 on very sticky tires in my car), but being able to go through corners without lifting off the throttle is more than worth it. For some people who do a lot of track driving, a fixed bias ratio such as with a clutch pack type LSD might be preferable for powering through corners or in cases where you want to break the rear end loose a little more. I use the car for autoX and daily driving, and the Wavetrac is really great for all of that. In the past, I found that an OEM E30 LSD would cause the inner wheel to break loose a little more than I liked sometimes at autoX events.

Whatever the case is, the MFactory diff you have sounds like it is either not working correctly, or there is a lot more to the break-in procedure than indicated.