[shivaswrath]

Originally Posted by tdizzle

That's ridiculous. You can buy a better one for cheaper with aftermarket. But then again there will be those that say it's OEM and has a warranty. See: PPK vs JB4 - one gives you more for cheaper but isn't a BMW backed product.

yeah that's true...and I suspect they'll have some slick programming with the PPK to give it a little more DSC (or is it less?) so when you're on it, a little tail slide is ok around the track...I don't like autox'ing with this much power and no diff, I'm just spinning my inner tires.

With a 6 year/100k warranty, OEM is my priority for sure...

[tdizzle]

Originally Posted by shivaswrath

yeah that's true...and I suspect they'll have some slick programming with the PPK to give it a little more DSC (or is it less?) so when you're on it, a little tail slide is ok around the track...I don't like autox'ing with this much power and no diff, I'm just spinning my inner tires.

With a 6 year/100k warranty, OEM is my priority for sure...

I'd presume with the diff working the dsc should have less work to do. Really all it does is brake and pull power to keep things in line.

[DVC]

Originally Posted by F30form

...30% is about the limit for most OEM LSD applications. Provides enough longevity and safety on the street while still being able to power out of corners on track. The original Factory BMW LSDs back in the day were only 25%...

That's my thought as well. I know Quaife doesn't publish their lock-up percentages - probably to keep from feeding into the misunderstanding that you need a high percentage to be effective.
There are a LOT of aspects to get right for an LSD to add traction without creating new problems... for example, a 2-way diff (and to a lesser extent, 1.5-way diffs) can add significant understeer when they lock-up on deceleration; 1-way diffs don't suffer from this, but they also function like open diffs under engine braking conditions.
There's also the manner in which the diff locks-up (i.e. how aggressive is the engagement force in response to input torque), whether the lock-up is variable, etc.
I would be willing to bet that BMW will be releasing something that is a well-balanced product that will offer appreciable traction improvements without creating other new handling challenges. Will it be a variable unit like those fitted to the e46 M3? Or a 2-/3-clutch unit with limited lock-up like OEM LSDs of the past? I dunno, and that's what I'd like to find out. At this point, I am open to the BMW LSD as a possible alternative to the Quaife. The Quaife is a great unit, but the possibility of the BMW option better integrating with DSC/DTC/eLSD is a compelling prospect.

[shivaswrath]

Originally Posted by DVC

That's my thought as well. I know Quaife doesn't publish their lock-up percentages - probably to keep from feeding into the misunderstanding that you need a high percentage to be effective.
There are a LOT of aspects to get right for an LSD to add traction without creating new problems... for example, a 2-way diff (and to a lesser extent, 1.5-way diffs) can add significant understeer when they lock-up on deceleration; 1-way diffs don't suffer from this, but they also function like open diffs under engine braking conditions.
There's also the manner in which the diff locks-up (i.e. how aggressive is the engagement force in response to input torque), whether the lock-up is variable, etc.
I would be willing to bet that BMW will be releasing something that is a well-balanced product that will offer appreciable traction improvements without creating other new handling challenges. Will it be a variable unit like those fitted to the e46 M3? Or a 2-/3-clutch unit with limited lock-up like OEM LSDs of the past? I dunno, and that's what I'd like to find out. At this point, I am open to the BMW LSD as a possible alternative to the Quaife. The Quaife is a great unit, but the possibility of the BMW option better integrating with DSC/DTC/eLSD is a compelling prospect.

Chatted with parts dude at BMW dealership, he said it's a clutch type with 30% lockup....
Jives with this here too:http://www.f30post.com/forums/showthread.php?t=866546

They can't get me an installation guide OR hours to do it...I was like how the F am I supposed to order something if I don't know how much the install with cost?!!

[DVC]

Originally Posted by shivaswrath

Chatted with parts dude at BMW dealership, he said it's a clutch type with 30% lockup....
Jives with this here too:http://www.f30post.com/forums/showthread.php?t=866546

They can't get me an installation guide OR hours to do it...I was like how the F am I supposed to order something if I don't know how much the install with cost?!!

Same here...

I did find that it's apparently a Drexler unit, though - which is a good thing, as they are regarded as being among the best available. I am somewhat doubtful at this point that there will be any specific integration with DSC/DTC/eLSD, though; maybe this really isn't necessary anyway.

I've got someone working on getting some more intel - I'll update this thread with any new info.

[Greenkirby21]

Originally Posted by DVC

Same here...

I did find that it's apparently a Drexler unit, though - which is a good thing, as they are regarded as being among the best available. I am somewhat doubtful at this point that there will be any specific integration with DSC/DTC/eLSD, though; maybe this really isn't necessary anyway.

I've got someone working on getting some more intel - I'll update this thread with any new info.

that would be much appreciated!

I've been trying to order an M235i since launch with the optional LSD which was suppose to be available at launch in march. But nobody at BMW, not my dealership or BMW NA customer service, knows anything about the LSD.

[Newton2001]

Hi,
I'm asking though I know the answer, but we never know: does it fit on a xDrive car to give it a more "fun to drive" handling ?

[shivaswrath]

Originally Posted by Newton2001

Hi,
I'm asking though I know the answer, but we never know: does it fit on a xDrive car to give it a more "fun to drive" handling ?

Only rwd n55 automatic drive trains currently...Why would the x Drive need one, don't you have a differential in the rear and center?

[shivaswrath]

Originally Posted by DVC

Same here...

I did find that it's apparently a Drexler unit, though - which is a good thing, as they are regarded as being among the best available. I am somewhat doubtful at this point that there will be any specific integration with DSC/DTC/eLSD, though; maybe this really isn't necessary anyway.

I've got someone working on getting some more intel - I'll update this thread with any new info.

I went to Drexler site, if it is indeed them, which it seems it might be (saw a 1 addicts post), then it's probably their multiplate torque sensing unit... Looks great, clearly a step above quaife units I've seen.

[DVC]

Originally Posted by shivaswrath

Only rwd n55 automatic drive trains currently...Why would the x Drive need one, don't you have a differential in the rear and center?

Yes, the M Performance LSD is for RWD only. Bummer though, as xDrive shifts torque within a given axle electronically by making use of ABS (similar to the RWD's eLSD), so it would also really benefit from a good mechanical rear LSD... similar to the optional rear LSD on the Audi S4.

[shivaswrath]

Nice review of the unit here: http://www.e90post.com/forums/showthread.php?t=591635

[DVC]

Originally Posted by shivaswrath

Nice review of the unit here: http://www.e90post.com/forums/showthread.php?t=591635

I stumbled upon that review as well...hard to say how similar the new M Performance LSD will be to that particular Drexler, though, as Drexler makes many different types of units.

[DVC]

Well, here's the skinny on the LSD:

http://www.f30post.com/forums/showthread.php?t=982935

After doing some research, I've discovered this is a 3-clutch unit... seems like a really solid option.

[utenigma]

So what I find interesting here, is from the 3d models on that article the ring gear for the MPerf LSD is bolted, not welded

This might mean one could at some point get ahold of a ring gear for a MPerf LSD separately (this is a big might) then use that gear, along with a different LSD unit and retrofit your existing pumpkin easily...

[DVC]

I have an appt. to get this LSD installed next Friday... $2698 (+tax) installed at Flemington BMW.

[Dog Face Pony Soldier]

Originally Posted by DVC

I have an appt. to get this LSD installed next Friday... $2698 (+tax) installed at Flemington BMW.

$2886.86 installed (including sales tax) makes this upgrade even more tempting. Although my bank account curses you DVC, I appreciate the info!

[The Nerd]

From an extreme newbie...is there any performance benefit for someone who doesn't track his car (like myself)?

[Gio72]

Originally Posted by The Nerd

From an extreme newbie...is there any performance benefit for someone who doesn't track his car (like myself)?

It improves traction on wet surface and snow

[DVC]

Originally Posted by The Nerd

From an extreme newbie...is there any performance benefit for someone who doesn't track his car (like myself)?

It improves traction considerably. Do you ever get the DSC/traction control light to come on while driving? If so, you'll see improvements on the street too...

[F30form]

Originally Posted by DVC

I have an appt. to get this LSD installed next Friday... $2698 (+tax) installed at Flemington BMW.

You must report back today!! Remember the 500mi break in though

[DVC]

Originally Posted by F30form

You must report back today!! Remember the 500mi break in though

It's being installed as I type this... gotta force myself to be patient for 500 miles

[focal]

Originally Posted by DVC

It improves traction considerably. Do you ever get the DSC/traction control light to come on while driving? If so, you'll see improvements on the street too...

NEVER…only in the snow. the LSD is wasted on me if I ever get it or it's available on a N20.

but do report back on your results.