LSD - Ready to pull the trigger tell me what to get

[chris_flies]

Originally Posted by jcrane82

If you swap the open diff to a LSD you will need to set backlash. How did you install one, reuse OEM bearings, and not check/adjust backlash? Machining tolerances will be different from one unit to the next, and a couple thousandths of an inch matter.

I reused OEM bearings and one of the lock rings, with an aftermarket lock ring and shims on one side. The one lock ring got bent, so I had to re-shim to the new lock ring ($200 shim kit...ugh). I started shimming using the original thickness engraved on the bent lock ring, and it ended up being perfect. I was going to measure regardless, but everything I've read said that it will remain in-tolerances.

Matticus91 Bird's and Quaife are like the O.G. LSD retrofitters for the E9x/E8x. Chris Harris did a review on a Hartge E92 335i with a Quaife LSD.

[Suprgnat]

Originally Posted by Matticus91

I know I know.... I alone have started threads on this topic many times lol.

I'm ready to go for an LSD, tell me what to buy and why. Looking for people who have done this already and have experience with an LSD in their E82.

Car is a 2013 135i 6MT

I want to get a full pumpkin so I can bolt it right up

Props to diffsonline. Not cheap, but silent, smooth, and predictable. Got their 3-clutch 35/60 in a 3.64. They now have a 4-clutch that I would have ponied up for in a 3.73 for the same price.

Edit: Oh. And the hook-up is amazing and controllable.

Edit: No 4-clutch for the 135i in manual.

[ShocknAwe]

Originally Posted by Matticus91

Would you be comfortable doing a cost breakdown? Honestly this seems to be a pretty linear decision set as far as price vs value but it's good to hear opinions at each price point. If I could be at under 2k for just the Diff I'd be very happy.

Also did you do the full pumpkin or just diff?

Sure. I got the full pumpkin from synchrotech. You do NOT want to deal with the machining necessary for our welded ring.

MFactory 3.08 Diff in Large casing was $2500 with core I believe. Maybe a bit more, came with paid return shipping label for the stock diff.
Bimmerworld aluminium RSFB $280
YCW Reinforced axles $1000

I also did M3 lower camber links, sourced those from a pick and pull for $80 each
YCW custom valved M3 rear dampers $300ea
HPA custom M3 rear headlight bracket $60

Plus shipping for the random bits, and hardware. Hardware was around $100 total

Make sure you have a diff lockdown of some sort too. Tons available. BMS has a new one that is cheap and looks solid as hell. I have one made by a forum member, been on for probably 2 years and doing fine.

True solid RSFBs have to be pressed in to the subframe, so factor some shop install costs. I had it all done as I'm now working 80hr+ weeks and have zero time to work on my car anymore. Added a solid chunk to the cost of the job.
I don't say this to be a woe is me thing, just don't forget about install costs when tallying for a big job like this.

[zx10guy]

Originally Posted by ShocknAwe

Sure. I got the full pumpkin from synchrotech. You do NOT want to deal with the machining necessary for our welded ring.

MFactory 3.08 Diff in Large casing was $2500 with core I believe. Maybe a bit more, came with paid return shipping label for the stock diff.
Bimmerworld aluminium RSFB $280
YCW Reinforced axles $1000

I also did M3 lower camber links, sourced those from a pick and pull for $80 each
YCW custom valved M3 rear dampers $300ea
HPA custom M3 rear headlight bracket $60

Plus shipping for the random bits, and hardware. Hardware was around $100 total

Make sure you have a diff lockdown of some sort too. Tons available. BMS has a new one that is cheap and looks solid as hell. I have one made by a forum member, been on for probably 2 years and doing fine.

True solid RSFBs have to be pressed in to the subframe, so factor some shop install costs. I had it all done as I'm now working 80hr+ weeks and have zero time to work on my car anymore. Added a solid chunk to the cost of the job.
I don't say this to be a woe is me thing, just don't forget about install costs when tallying for a big job like this.

Would you provide more details about the return shipping for the core? That's pretty good they pay for the shipping of your old core. Who is the shipping company and do you just arrange for a pickup?

[ShocknAwe]

Originally Posted by zx10guy

Would you provide more details about the return shipping for the core? That's pretty good they pay for the shipping of your old core. Who is the shipping company and do you just arrange for a pickup?

Dunno what to expand on. I paid for shipping from synchrotech and they sent a return label for my core. The shop has a pickup by shipping companies and handled boxing up the core and calling a pickup for me.

[Zombie_Head]

Originally Posted by Matticus91

I haven't heard of them, and can't quite figure out what their deal is from the website lol. Do they sell diffs? I'm in the USA though and not sure it'd be financially reasonably to ship a diff over from the UK vs buying stateside

One of the first businesses to create a quaife diff for BMWs, they have nothing but positive reviews on pretty much any BMW that receives their diffs. From the E82 120d in Europe all the way to big power 335is pushing 500-600hp on the street and track.

They have a German dealer and installer, they confirmed that the diff for my 125i is a simple replacement (not welded like the 135i), comes with a lifetime manufacturing warranty (i know but just saying what i was informed).

Got quoted €1,800 including the install, fluid, diff etc. Will be a great time to replace those soft diff carrier bushings/diff mount bushings with 1M/M3 ones for even more stability, if i plan things correctly i should be booking in my car for that diff before Christmas myself.

If you search the E9x forums regarding "Birds" or "Quaife", someone did a detailed review on his car (335i with 420-ish hp) and reported how quiet is it on the road and did 2-3 days on Nürburgring laps without any issues.

[Dackelone]

Originally Posted by Matticus91

I haven't heard of them, and can't quite figure out what their deal is from the website lol. Do they sell diffs? I'm in the USA though and not sure it'd be financially reasonably to ship a diff over from the UK vs buying stateside

They were one of the first places, to offer diffs on an exchange basis for 1ers. I also have no idea on shipping... but I suspect it would be too much to be feasible. ? It wouldn't hurt to ask them, though.

A friend over here bought his LSD(a Quaife) thru them... cost him around 1,300 pounds(but this was several years ago) in the end with shipping to Germany. Afterwards he shipped his core back to them. He really likes his LSD.

I just thought I point them out to you.

Dack

[crowtrobot]

Another vote for diffsonline here. Dan was very responsive and helpful with my questions.

I went with a Wavetrac with a change in ratio to 3.73. I'm very satisfied with the street manners and the performance on the track. I believe it was somewhere in the neighborhood of $2400 for the full pumpkin. Good luck with the shopping!

[Zombie_Head]

Originally Posted by Dackelone

They were one of the first places, to offer diffs on an exchange basis for 1ers. I also have no idea on shipping... but I suspect it would be too much to be feasible. ? It wouldn't hurt to ask them, though.

A friend over here bought his LSD(a Quaife) thru them... cost him around 1,300 pounds(but this was several years ago) in the end with shipping to Germany. Afterwards he shipped his core back to them. He really likes his LSD.

I just thought I point them out to you.

Dack

The German QUaife dealer even informed me, that this diff takes very "simple" fluid, nothing special like that M diff fluid or similar, they sell that fluid as well, granted i never asked the price.

[iminhell1]

I got a MFactory 3.46 last Black Friday from Syncrotech. Did the install myself and reused everything except seals, there was no chance of saving them.

I didn't check anything. I just put things back where they came from. 20K+ later, no issues I know of.

BUT, I think I should have done measurements. I have a Torsen in my Focus and it acts completely different; you absolutely know it's there.
The 135, not so much. Vs the e-diff I don't feel it was night/day difference. Yes it'll help. But I don't see anyone who's really dug into 'tuning' the e-diff and chassis control. SOP is code out and get mechanical because I don't understand or like computers. Which works, but is an incomplete story.

[chris_flies]

Originally Posted by iminhell1

I got a MFactory 3.46 last Black Friday from Syncrotech. Did the install myself and reused everything except seals, there was no chance of saving them.

I didn't check anything. I just put things back where they came from. 20K+ later, no issues I know of.

BUT, I think I should have done measurements. I have a Torsen in my Focus and it acts completely different; you absolutely know it's there.
The 135, not so much. Vs the e-diff I don't feel it was night/day difference. Yes it'll help. But I don't see anyone who's really dug into 'tuning' the e-diff and chassis control. SOP is code out and get mechanical because I don't understand or like computers. Which works, but is an incomplete story.

Agreed. It's fine just removing the ediff feature, but you really need to change a few more things.

I did a little bit of messing around in the DSC module; ended up changing a bunch of brake and 'nanny' things that everyone who goes in there ends up coding-out, but I also decided to explore inputting 1M values in for the oversteer coefficients. It made DTC mode less like a useless gimmick mode, and more like a proper goldilocks step between the nanny state that is default, and sideways at the slightest breath of throttle. It's perfect for driving in the rain, as it doesn't interfere too quickly. You can get sideways and crank-out some serious wheel spin (128i spinning in second is hysterical) but it'll step in relatively gently when you get too far out of whack, which is reassuring.

The real difference made by the 'proper' diff being installed, happened after removing all of the nannies so that the darned thing could do its job. Now it's just a wonderful balance; grip when you need it, slip when you don't want it.

[jcrane82]

Originally Posted by iminhell1

...
I didn't check anything. I just put things back where they came from. 20K+ later, no issues I know of.

BUT, I think I should have done measurements. I have a Torsen in my Focus and it acts completely different; you absolutely know it's there.
The 135, not so much. Vs the e-diff I don't feel it was night/day difference. Yes it'll help. But I don't see anyone who's really dug into 'tuning' the e-diff and chassis control. SOP is code out and get mechanical because I don't understand or like computers. Which works, but is an incomplete story.

Which MFactory differential type did you install? I am quite surprised to hear that there wasn't a night/day difference compared to stock. If you installed a clutch type, you may have not set the preload correctly and the differential is acting like an open. With a helical/Torsen, having too much backlash will usually just cause additional noise/clunking.

Everyone codes out the eLSD after installing a mechanical LSD because that is what you should do. With a proper mechanical LSD you don't want any braking intervention from the ABS system as the mechanical LSD has that covered. There have been pretty decent advancements in eLSD software technology since the E82 was launched, but unless you are a software engineer at BMW, there is no hope for getting updated algorithms into the DSC module. Also keep in mind that the factory eLSD is setup with factory parts in mind. The minute you change tires to something other than factory spec, the system variables have changed and it will not behave the way engineering set it up.

The eLSD is great for BMW as it gives them a "free" differential on a non M-car. And for the vast majority of appliance driving consumers it is good enough as it prevents some wheel spin for starting from a stop on slippery surfaces. Where it fails is the predictability, since the system doesn't intervene until it senses slip. Trying to drift in the snow with the factory open eLSD vs. a proper mechanical LSD is worlds different.

[Matticus91]

Originally Posted by jcrane82

...Trying to drift in the snow with the factory open eLSD vs. a proper mechanical LSD is worlds different.

Great post, this was my favorite part. Time to go shopping lol

[chris_flies]

Originally Posted by Matticus91

Great post, this was my favorite part. Time to go shopping lol

Drifting is a great way of marketing I can't wait to drive the car in some actual snow this winter.

[Zombie_Head]

May i ask, does the whole RSF need to be dropped out of the car to get a LSD installed (including M3 diff bushings front and rear) on a 125i/128i?

[crowtrobot]

Originally Posted by Zombie_Head

May i ask, does the whole RSF need to be dropped out of the car to get a LSD installed (including M3 diff bushings front and rear) on a 125i/128i?

Nope, not at all. Remove the bolts from the input flange to the drive shaft, remove the bolts on the output flanges to the rear axles, then put a jack under the diff and remove the bolts to the rear subframe and lower the diff down with the jack.

Definitely helps to have a second to operate the jack while you guide the diff out and prop it up.

I did it on jackstands over the course of an evening and a morning, but I was slow, and the driveshaft needed to soak in PB Blast to loosen off the diff.

[Zombie_Head]

Originally Posted by crowtrobot

Nope, not at all. Remove the bolts from the input flange to the drive shaft, remove the bolts on the output flanges to the rear axles, then put a jack under the diff and remove the bolts to the rear subframe and lower the diff down with the jack.

Definitely helps to have a second to operate the jack while you guide the diff out and prop it up.

I did it on jackstands over the course of an evening and a morning, but I was slow, and the driveshaft needed to soak in PB Blast to loosen off the diff.

Got this confirmed by the QUaife dealer locally.

[asiflicious]

I got the M Factory helical for my 135i. It is an improvement but definitely not a night and day improvement. It will make hooning around a lot more enjoyable but as far as actual grip and performance, the stock e-diff worked just as well. I don't notice much of a difference with the LSD. Maybe I need to drive a stock diff 135i and my car back to back to really notice it

[duder13]

Originally Posted by asiflicious

I got the M Factory helical for my 135i. It is an improvement but definitely not a night and day improvement. It will make hooning around a lot more enjoyable but as far as actual grip and performance, the stock e-diff worked just as well. I don't notice much of a difference with the LSD. Maybe I need to drive a stock diff 135i and my car back to back to really notice it

Interesting. I've been thinking about adding an LSD in the coming year, but I've been waffling on it a little. Neither my 911 nor Cayman had a mechanical LSD, and no current McLaren cars come with one, so there is some precedent for having an electronic LSD in fast cars.

[chris_flies]

Originally Posted by duder13

Interesting. I've been thinking about adding an LSD in the coming year, but I've been waffling on it a little. Neither my 911 nor Cayman had a mechanical LSD, and no current McLaren cars come with one, so there is some precedent for having an electronic LSD in fast cars.

Agreed, but that is comparing a mere first-gen BMW system used in every single one of their cars, to a quarter-plus million dollar car that pushes all technical and physical boundaries possible. The beauty of the helical LSD is that it performs the same exact function as the eDiff, so it will feel the same performance-wise (because the eDiff does a very good job), but with more playfulness (it is a mechanical system that reacts instantly).

I think you'd feel the biggest difference with a locking LSD. The action of locking and unlocking, and then how much it actually locks completely changes how the car behaves. It's a very predictable, simple, and delightful experience when you're pushing it on the track. On the street, however, it's either (A) a noisy, clunky, chattery thing that makes pulling out of parking lots in an overly-calm fashion a tire squealing affair, (B) a psychotic device that tries to kill you if you even think about touching the throttle in a corner that's wet on tires that aren't meant to be in the wet, or (C) your bestest friend that ensures that you will depart that Chick-fil-a drive, in front of that impending Prius with absolute predictability, and a possible hint of sideways exuberance.

Matticus91
My answer to your thread:

If you want a stock-like feel, a quiet nature, and the ability to do relatively fun things with ease, go for a helical. I'd personally go with a Wavetrac, as it alleviates some concerns of having absolutely no locking effect when one wheel has no traction. I imagine this is what you will go for...

If you want a very different driving experience, a race car-ish experience, and the ability to very fun things, very easily, and very controllably, go for a clutch-type. I'm partial to my MFactory 1.5-way, I love the way it feels out-of-the-box, and it came with things to adjust it if I want to (which I might eventually). I can't wait for some proper amounts of snow to test the traction of this diff vs the eDiff, I have fairly high expectations (for entertainment purposes, of course).

[duder13]

Originally Posted by chris_flies

Agreed, but that is comparing a mere first-gen BMW system used in every single one of their cars, to a quarter-plus million dollar car that pushes all technical and physical boundaries possible. The beauty of the helical LSD is that it performs the same exact function as the eDiff, so it will feel the same performance-wise (because the eDiff does a very good job), but with more playfulness (it is a mechanical system that reacts instantly).

Absolutely, in terms of the McLarens, but my Porsche 996 and 987 had relatively basic e-diffs, and they’re still considered great driver’s cars, so I’m trying to decide if it’s worth it. I’m sure I’ll still get one.

[iminhell1]

As an argument to my lack of understanding/tuning of the ediff,

The recent drift world record by the 2018 M5, I've been looking and looking as to the technical changes they made to accomplish this feat. Bupkis.
But I don't feel it's that out of line in thinking that they made changes to the control modes to make the car accomplish this. It's so computer controlled that it should be self evident IMO.
Thinking that, I don't see that a straight mechanical diff is the end all/be all for the ultimate handling machine or the best driftorz car. There needs to be a balance of both the mechanical and the electronic.


I know full well that the amount of TQ I try to put down is too much for the tires and the diff out of corners. If I WOT the car will not step out, it's just gone right now. It can't react fast enough. The ediff will kick in before the mechanical though. But when I turn power down, the mechanical hits before the ediff. So there is a correlation error I need to work on adjusting. I just haven't had the conditions to play enough yet.