[FC4]

Originally Posted by DVC

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

Read up on proper LSD break-in. It is not mileage dependent. You can break it in in half an hour.

[DVC]

Originally Posted by DVC

...Do you ever get the DSC/traction control light to come on while driving?...

The snow... another area of improved traction I am looking forward to ; )

[DVC]

Originally Posted by FC4

Read up on proper LSD break-in. It is not mileage dependent. You can break it in in half an hour.

Not surprising... The 500 mile recommendation is probably akin to BMW's recommendation for a 1200 mile initial car break-in.

Any resources you know of for best practice clutch LSD break-in?

** Edit: Here's an interesting break-in procedure doc...

[jetbill]

Can't wait for the report back!

[FC4]

Originally Posted by DVC

Not surprising... The 500 mile recommendation is probably akin to BMW's recommendation for a 1200 mile initial car break-in.

Any resources you know of for best practice clutch LSD break-in?

** Edit: Here's an interesting break-in procedure doc...

That procedure is fine...but again mileage is mentioned there. That link indicates 1200 miles, and that's absolutely not necessary.

http://www.kaazusa.com/techhelp2.html

A half hour of figure-8s at low speed will suffice. Then just change the fluid again and it's good. But BMW's recommendation of "taking it easy" for 500 miles with no other specific procedure/info is useless.

[DVC]

Originally Posted by FC4

That procedure is fine...but again mileage is mentioned there. That link indicates 1200 miles, and that's absolutely not necessary.

http://www.kaazusa.com/techhelp2.html

A half hour of figure-8s at low speed will suffice. Then just change the fluid again and it's good. But BMW's recommendation of "taking it easy" for 500 miles with no other specific procedure/info is useless.

BMW also says it's not necessary to change the diff fluid after break in... not sure how I feel about that

[shivaswrath]

Originally Posted by DVC

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

WOAH!!
Let me know how it goes, they're only 24 miles from me....actually, can we get together after so I can get a sense?

[shivaswrath]

Originally Posted by FC4

That procedure is fine...but again mileage is mentioned there. That link indicates 1200 miles, and that's absolutely not necessary.

http://www.kaazusa.com/techhelp2.html

A half hour of figure-8s at low speed will suffice. Then just change the fluid again and it's good. But BMW's recommendation of "taking it easy" for 500 miles with no other specific procedure/info is useless.

It's a sealed unit, so you can't change fluid out.

It lasts life of the unit....(see FAQ details above).

[DVC]

LSD is installed!! Initial impressions are very good... I haven't given it a real test yet of course, but even cornering easy I can tell that it lays power down to the ground like an M car. No weird noises or clunks st all.

Initial break-in was interesting... driving around in figures 8s and circles in Home Depot parking lot for like 20 minutes garnered some stares and strange looks.

Originally Posted by shivaswrath

WOAH!!
Let me know how it goes, they're only 24 miles from me....actually, can we get together after so I can get a sense?

Sounds good - I'll PM you...

[ska///235i]

nice, the m perf lsd is made by Drexler..$2700 install is a fair price with bmw warranty

Originally Posted by DVC

LSD is installed!! Initial impressions are very good... I haven't given it a real test yet of course, but even cornering easy I can tell that it lays power down to the ground like an M car. No weird noises or clunks st all.

Initial break-in was interesting... driving around in figures 8s and circles in Home Depot parking lot for like 20 minutes garnered some stares and strange looks.



Sounds good - I'll PM you...

[F30form]

Originally Posted by shivaswrath

It's a sealed unit, so you can't change fluid out.

It lasts life of the unit....(see FAQ details above).

Its not sealed, but it is a pita to change out the fluid. It has a fill hole on the top of the case. Gotta pull the unit to drain the fluid. But correct, not necessary to change the fluid after break in.

[shivaswrath]

Originally Posted by F30form

Its not sealed, but it is a pita to change out the fluid. It has a fill hole on the top of the case. Gotta pull the unit to drain the fluid. But correct, not necessary to change the fluid after break in.

Yes, sorry, there's a fill hole...but there's no drain plug, right?

[F30form]

No drain plug. The case (pumpkin) is the same as the regular series differential.

[jetbill]

Here's some pictures guys:

[DVC]

Cool...did you decide to install it yourself? What are your impressions from a technical/hardware perspective? I'd also be curious how much heavier it is than the stock unit...

[DVC]

Originally Posted by shivaswrath

...actually, can we get together after so I can get a sense?

Got your IM - tried to reply but your inbox is full...

[F30form]

Anyone have a review after breaking in the diff?

[jetbill]

Still breaking it in but have some track time scheduled for Sunday.

In summary, it affects many different aspects of the "overall" daily driving experience. It's very quite, you wouldn't know it is back there other than the "feel" of the car.

Under moderate acceleration the car just pulls like a freight train, shift into each gear are more evident by the increased whiplash ;-).

Braking the car feels much more stable in a straight line.

Turning hasn't changed much.

Overall much more confidence in the car, the power feels much more appropriate for the drivetrain and suspension with the LSD.

Will know a bit more after Sunday.

[utenigma]

Originally Posted by jetbill

Still breaking it in but have some track time scheduled for Sunday.

Were you able to get out on Sun?

[jetbill]

Originally Posted by utenigma

Were you able to get out on Sun?

Yes, boy was it hot....
Considerable difference in handling, mostly noticeable during braking and straight line stability and exit in all scenarios.

Takes a bit getting used to but I would say anyone whom is above stock power level is a must.

I ran this weekend on R- compounds (R888's) with about 2.5 degrees of front camber on Map 2. Next week I'm going to try running my DD setup of staggered 19's with RE-11's.

Definitely an improvement on the AutoX track, I won't be doing any DE's during the summer so I'll have to wait a few months for some real track feedback.

I had the dealership do the install since their was a change on the design from the E9X platform that I was unfamiliar with.

It's more like a CV joint instead of flanges to the half-shafts with lots of BMW special tools required (I really almost tried it with a CV joint puller that has a slide hammer).

Even though the BMW slides show 2.5 hours , the dealer wanted 5. They came down to 3 and I was very happy with that.

Second to suspension mods or a tune, this is an absolute must for those who track.

[DVC]

Mine was installed on May 23rd, so I've had a bit of time now to break it in properly and get a good feel for the differences. I haven't had it on the track where its benefits really come to light, but even on the road it feels great...

Ordering/Installation:
I bought mine from Flemington BMW, and had them install as well. Their price was the cheapest I've seen ($2358.56), and they honored BMW's install spec time of 2.5 hours, so the labor expense was not bad at all.

Break-in:
I followed the Diffsonline break-in procedure, which basically consists of driving in 20 full-lock figure eights at idle speed, then 20 full-lock circles in each direction, also at idle speed. (I got lots of perplexed looks in the Home Depot parking lot while doing this ; ) During this process, I heard no clunks, whines or any other weird noises. There were some miles on the car between drop-off and pick-up, so maybe the install included some basic break-in.

Overview:
It's not a night and day difference in most situations, but you can definitely feel the LSD working. Unlike torque-biasing helical differentials (Torsen, Quaife, etc.), which act as open diffs until a wheel slip exceeds a predetermined bias ratio (e.g. 2.1:1), then respond by engaging lock-up... clutch-style LSDs kinda take the opposite approach by applying lock-up to the half shafts - before wheel slip - under acceleration, and then allowing some slippage to compensate for wheel rotation speed variances, etc. Also, 1.5 way units like the M Performance LSD also apply some lock-up under braking as well (only 9%, as too much can lead to serious understeer), which helps keep both rear tires rotating under hard braking. Without getting too technical, you can feel the increased stability under acceleration an braking.

Perceptions on the Road:
When hammering the gas as you exit a turn, the car lays down power like a beast. You can feel the tires pushing with equal power. Then in a corner, you can feel the clutches working by allowing the inside tire to rotate more slowly; the result is the outside wheel really pushing you around the corner, and killing off understeer. It's not always obvious, but if you pay close attention, you can notice the effect even just driving around "enthusiastically" on the street.
It's still possible to throttle-induce rear tire slip, of course - but the threshold is higher. And when it happens, both rear tires slip together... so even though the traction threshold is higher, the slippage characteristics seem less "edgy" and more predictable, making it less obtrusive and easier to control.
The small amount of lock-up on braking is also a welcome improvement...it really makes the car feel rock steady when braking hard. I understood this in theory, but I guess I wasn't expecting to feel much of anything, so it was a nice surprise.


Looking forward to getting the car back on the track to see how the improvements feel when pushing the car to the limits of my abilities.

[Dog Face Pony Soldier]

I should probably unsubscribe to this thread before I order one of these LSD! The mid-corner jerkiness of sliding the rear end with the e-diff has me yearning for the organic feel of a proper LSD.
Trying to keep my head in the sand...