What did you do to/for your 1er today?

[xQx]

I got a M-Factory clutch-type LSD installed yesterday. In another thread someone was foolish enough to ask me what i thought, to which I've got a very verbose answer, which I'm copying & pasting here for anyone else thinking about a LSD
--

Because I'm in Brisbane and used one of Mike's (difflab Australia) recommended tuning shops to do the work, they took the diff out first thing in the morning, Mike collected it, replaced the core, setup the new diff and dropped it back at 3pm, so the car was ready to go at 5:30pm.

It seems everyone is going helical these days, but the boys in Brisbane told me while they've got some advantages (not least of which is cost), they've driven cars with a particularly bad habit - the helical can rapidly and unpredictably move the torque from one wheel to the other. Meaning when you're right on the edge of traction (or drifting), you can get unpredictable squirrely behaviour from the back end. The more power you have, the more pronounced it is but they've seen it in cars with 350whp+. Since this was _exactly_ the behaviour I was trying to get rid of by getting a LSD, I took the road less travelled and got a good old-fashioned clutch-type diff.

The good news for me was in my pumpkin size, the Mfactory 10-plate clutch-type diff was the same price as the helical.

I've never had a car with a mechanical diff before, and I gotta say I was a bit nervous spending $3k ($1.5k for the diff, about $400 - $500 for Mike's work & oils etc, about $500 for the diff removal and replacement and about $500 for new PowerFlex diff bushes & Installation) on a mod that I wasn't quite sure what it was going to do... I was laughing with the boys in the shop saying "well I bloody hope it makes a difference"... they assured me 'clutch-type, oh yeah, don't worry about that, you'll notice a difference".

And it did. It _totally_ changes the car.

Since I've never previously driven a car with a mechanical LSD, I've read every bloody thread I could find about people putting LSD's in 1ers and 3ers, and not one of them mentions bad behaviours. I guess people don't like handing out big money then admitting it didn't do exactly what they wanted/expected, or people don't want to winge. Either way, I've got some feedback that I would be really surprised if it was unique.

First, there are some common concerns about getting a LSD:
1. Diff noise. Let’s be clear, when you read Diff noise, you think Diff wine. Like the sound an old taxi makes. This is a non-issue. There's none. I'd be surprised if any diff on the market wined if installed and maintained properly. From what I've read, if you install solid aluminium diff-bushes you get substantial NVH and diff wine. That's the bushes, it's not because you changed the diff.

2. Diff noise / Slow-Speed Engagement feedback. What people actually mean when they refer to LSD diff noise, is the sound of the plates engaging when you're doing a tight turn at low speed. (ie. in a car park) The M-Factory diff has 10 plates, and mike configures it as 6, 8 or 10 plates engaged depending on how much or how little slip/give you want. 6 is good for street use, 10 for track use only. I'm told with 10 plates you get quite pronounced clicking & clunking from the back when it engages at low speed. As mine was setup (6 plates) there is no audible noise. However, there is a very pronounced shudder / vibration feeback on the steering wheel when I take a tight turn, especially when cold. (eg. out of the driveway in the morning). But the key thing here is it's like N54 injector tick or wastegate rattle. It's not an issue. It's not doing damage, it's normal operation and if you know what it is, it's not even annoying.

3. Extra NVH in the cabin. Absolutely none.

Now, I was initially concerned about 1 & 2, but reading other peoples posts laid those concerns to rest. I read somewhere a helical diff is easier for a daily driver because you basically don't know it's there. It's a drastic improvement over stock, but it's not made for drifting - so like stock - it doesn't matter what it does once you're spinning both wheels, if you're spinning both wheels - ease off. A clutch-type diff is much more noticeable and a bit disconcerting at first, but if you learn to drive it, they're more fun, more predictable and faster.

The critical thing to know about a clutch-type diff is there's no 60% lock, or 85% lock. It's open until it engages, then once it's engaged it spins both wheels equally until you overpower it's clutch (which will be 60% of maximum pressure, 80% of maximum pressure or 100% of maximum pressure depending on how you've set it up), then it'll let a wheel slip by slipping the clutch - once the clutch pressure overpowers the wheel's grip, it spins both at the same speed again.

So, here's the behaviour that nobody mentions - one which may be clutch-only, the other would be common to every LSD.

Under-steer.

So I'm on totally stock suspension, control arms etc. I've got non-runflat sticky tires but that's it. The 135i isn't known for it's composed, predictable handling when stock, and (like all road cars) BMW designed it to understeer.

When you have an open diff at the back and you drive around a corner, the wheel with the least resistance gets the torque (ie. your outside wheel). This a good thing. Because there's no torque on the inside wheel, it's not trying to push the car in any particular direction - the car will follow where the front wheels are pointed. (until your circular g-force overpowers front-end grip)

If you lock up the diff at the back, you suddenly have two sticky tires at the back of the car trying to push straight and forward. This puts considerable force on the front tires trying to plough understeer. If you get more grip at the back of the car than at the front, that's exactly what the car does.

Theoretically, with a helical, it'll try to put as much torque as it can on the inside wheel only - which may still track in the direction of the front wheels since most of the torque is going to one wheel, but also puts all your power to the wrong wheel. Until it looses grip and the torque gets put onto the outside wheel, this is exactly the opposite of what you want.

This is why modern cars use a viscous coupling - and have sensors on your steering wheel, throttle and g-force sensors to electronically drive the outside wheel more than the inside wheel by the %age required for the angle - thus driving the car exactly where you point the steering wheel. My previous X5 (4.8is) was amazing at this. You could drive around a right-hand corner at full throttle and the car would take the corner like a WRX. Every bone in your body was telling you the car should be slipping sideways like a bitch at these G's, but it'd drive exactly where it was pointed. (until it doesn't, then you've got 2.5 tonnes of truck hurtling sideways at 60km/h, fully subjected to the laws of physics and nothing the computer can do will save you. Incidentally, this is why I no longer have that X5.)

This is really, really noticeable. Now, if you're driving 'properly' around a track, you'll never get this behaviour (brake in to the apex, power out of the apex) - but on the road where you commonly accelerate through sweeping corners (eg. any right-hand turn where you've had to stop) - you can feel the car being pushed from the back and the track it follows is slightly wider than before. I've got years of experience driving subarus (which understeer like a bitch) and it feels like you're right about to break into plough understeer. I've been pushing the car every opportunity I get to explore this behaviour more and it actually doesn't seem to develop into plough understeer - but it also doesn't track exactly where the front wheels are pointed - it's strange, it feels like you're right on the edge of traction well before you actually are.

Also, if you ease off the accelerator halfway through the corner, it has a substantial impact on the balance of the car. It's almost as if you can feel the diff disengaging and the weight shifts rapidly to the front of the car. I haven't explored this behaviour enough to know what happens next, but it's very pronounced, nothing like standard, and not really a good thing.

So M3 control arms have just skyrocketed to the top of my mods list, along with anything else that will promote oversteer characterises; but I think a lot of these behaviours are probably best managed via driver experience & education.

(Now onto the good behaviours)

1. Oversteer
However, and here's the really fun part - If you're driving around a sweeping bend and it feels like if you give it slightly more power you'll be in a plough-understeer - if you do exactly that and give it a bit of power, the back predictably & reliably breaks loose slightly and rotates the car into the corner. It's amazing. It's exactly the opposite to what you'd expect, it's great fun, and very desirable!

After about 2 hours of driving I feel like I can step the back out of this short-wheelbase car with precision and confidence. I've never been anywhere near being able to do that before.

2. Grip
Also, a big reason why I got the LSD in the first place was to improve straight-line grip/acceleration. There's conflicting information about how much of a difference a mechanical LSD makes to straight-line grip over the e-LSD. I'd like to put that to rest: A LOT.

I was using 0-100 times as a benchmark for my power increase mods, until I reached the point where grip was my limiting factor. Adding a LSD has decreased my 0-100 time by 0.5 seconds consistently. Not only that, I can use first gear again. I still easily overpower the wheels in 1st and 2nd, but at 3/4 throttle I've now still got grip in first. It's a very, very nice thing to have back.

3. Forgiveness & communication
Lastly, and this is easily the biggest benefit. When I lost traction with the e-Diff, either in a straight line or powering around a corner - to regain traction meant coming off the power entirely. I actually found DTC did a much better job of this than I did, but basically you've got grip until you haven't, then with very little warning you've got nothing, and you (or DTC) have to come right off the power to get it again.

With the LSD, powering around a corner you can hear the inside wheel slipping well before the back-end steps out. When the back-end does step out, easing off the throttle slightly will regain it and you can power forward. When enabled, DTC engages only after the back has noticeably stepped out and it tends to engage for only long-enough to regain traction. (I always drive with DSC off). In a straight line, it's the same - there's far more grip until you start spinning, then easing off slightly will regain grip. If it's turned on, DTC will flutter the throttle for you seemingly for just long enough to regain grip, then it gives you full power back.

In short - driving the car is actually fun - when you exceed the limit you can regain easily. When you're near the limit you can feel it. If you're driving without disabling DTC it intervenes when it should, and it doesn't intervene by much.

So two obvious questions I've been asking myself:
1) Is a LSD worth the money, given that you can go from stock to FBO for less cash?
Yes. It makes the car more predictable and more forgiving at the limit. It gave me first gear back. It shaved half a second off my 0-100 times. It turned DTC into an ally, rather than an over-protective bitch that was trying to kill me by pulling all my power.

2) Had my time again, would I still go clutch-type over helical?
Oh hell yes.
Even though it's a bit of a hanful in corners, I'm confident I'll learn to manage it, and future mods will probably 're-balance' the handling of my car. But the predictability and ability to regain composure after a slip is amazing. And finally - drifting / oversteer is SERIOUSLY FUN!

If you wanted something to give you twice as much grip as stock with almost no downsides - yeah, go helical. But a clutch-type really rewards you for pushing the car at the limit, and while it introduces some undesirable characterisics, they can all be managed by the driver because it's completely and utterly predictable.

Finally, I had two other goals that i wanted to achieve by installing a LSD, and I'd like to say I missed them by a mile.
1) Better tire wear.
The logic goes that with a LSD, I'll loose grip less often and thus wear the tires less. No, no, no, no. Nothing could be further from the truth.
a) The inside back wheel will reliably loose grip in powering through a corner.
b) It's so much fun, so easy and predictable to step the back out around a left-hand bend, you find yourself doing it whenever you can.

2) Porche Boxter handling.
When you start messing with suspension and handling, find someone who knows what they're doing. It's all about balance.
Adding a LSD to the back of a car drastically changes the way the back wheels push the car. It needs to be countered with something equally aggressive at the front. Not doing so leaves you with a totally unbalanced car.
BUT - Balanced is nice. Balanced is preferable. But Balanced is far from necessary. PREDICTABLE is necessary. A fighter jet is horribly unbalanced. They're designed that way so they can manoeuvre fast. But they're predictable, so in the right hands, it doesn't matter. Given the choice between balanced or predictable I choose predictable.

What I've got right now reminds me of Richard Hammond's review of the Z4M: https://www.youtube.com/watch?v=0FTc...youtu.be&t=238

It wasn't what I was aiming for, but man, I'm happy with the result.

[chris_flies]

Originally Posted by Gray_Panther

197k 128i is the record, probably past 200k now with the new owner.

That's downright impressive!

[08 1ER]

I spent the last week painting the internals of my headlights. Color matched jet black instead of the grey surrounds and chrome bits. It was a PITA along with a lot of waiting for paint to cure and gas off but i think the outcome was well worth it. It really gives my black 135 a different look and i feel it works well with the overall appearance. Here's a before and after.

[Suprgnat]

Originally Posted by xQx

Also, if you ease off the accelerator halfway through the corner, it has a substantial impact on the balance of the car. It's almost as if you can feel the diff disengaging and the weight shifts rapidly to the front of the car.

Is your diff a 1-way, 1.5-way or 2-way? I have a 1.5 way (35/60 degree ramps) and have not felt this at all, in fact the opposite. The not-so-aggressive lock on decel has a nice stabilizing affect.

That aside, great write-up! Enjoy!

[Suprgnat]

Ordered a Blackvue DR750S-2CH front and rear dashcam. Looking forward to installing it soon, as well as the AKG DTM selector rod I've had lying around for a month now.

[Mr. Pharaoh]

Originally Posted by 08 1ER

I spent the last week painting the internals of my headlights. Color matched jet black instead of the grey surrounds and chrome bits. It was a PITA along with a lot of waiting for paint to cure and gas off but i think the outcome was well worth it. It really gives my black 135 a different look and i feel it works well with the overall appearance. Here's a before and after.

Looks good! How did you go about opening the housings? What paint did you use for the match?

[08 1ER]

Originally Posted by Mr. Pharaoh

Looks good! How did you go about opening the housings? What paint did you use for the match?

Thank you! Paint was from Microfinish paint code 668. I used a heat gun to open the lights. Takes a lot longer than an over but i wasn't willing to get a beatdown from the wife for cooking lights! I removed as much glue as possible and resealed them with new Butyl rubber sealant.

[Mr. Pharaoh]

Originally Posted by 08 1ER

Thank you! Paint was from Microfinish paint code 668. I used a heat gun to open the lights. Takes a lot longer than an over but i wasn't willing to get a beatdown from the wife for cooking lights! I removed as much glue as possible and resealed them with new Butyl rubber sealant.

HAHA! I can just imagine my woman waking up at 2am to find me secretly baking my headlights. Does the paint come in a rattle can?

[08 1ER]

Originally Posted by Mr. Pharaoh

HAHA! I can just imagine my woman waking up at 2am to find me secretly baking my headlights. Does the paint come in a rattle can?

Right? Yes it does come in a rattle can. I had plenty left over too. Select your year/make/model and they match it.
Microfinish.com

[Mr. Pharaoh]

Originally Posted by 08 1ER

Right? Yes it does come in a rattle can. I had plenty left over too. Select your year/make/model and they match it.
Microfinish.com

Thanks for the info. I'll check it out.

[08 1ER]

Originally Posted by Mr. Pharaoh

Thanks for the info. I'll check it out.

I also used Easy Off oven cleaner to remove the chrome from the chrome pieces.

[xQx]

Originally Posted by Suprgnat

Is your diff a 1-way, 1.5-way or 2-way? I have a 1.5 way (35/60 degree ramps) and have not felt this at all, in fact the opposite. The not-so-aggressive lock on decel has a nice stabilizing affect.

That aside, great write-up! Enjoy!

Thanks It's 1.5way - I think the drastic weight-transfer that I experience is a result of the very soft stock suspension. ... having driven for another few hours, it's also a very easy behaviour to avoid once you expect it.

[1and1]

If you haven't already, consider coding to disable the E-LSD functionality- it'll still be using the brakes to mimic LSD action and conflicting with your MLSD.

[Gangplank]

Installed a set of "is" kidney grills. Chrome outter/black inner. liking the subtle look.

[HyeWarrior]

My stupid thing keeps drinking coolant. Ugh.

[Esteban]

Originally Posted by Gangplank

Installed a set of "is" kidney grills. Chrome outter/black inner. liking the subtle look.

Nice choice imo. I did the same thing to my car some years ago. Contrary to popular opinion, I think they look better than all black grills, which is what a lot of people choose. You must as well or you wouldn't have got them. They are also the same grills that are on the 128i and the 1M, so that means only the 135i came stock with the all chrome grills.

[Gray_Panther]

Originally Posted by Esteban

Nice choice imo. I did the same thing to my car some years ago. Contrary to popular opinion, I think they look better than all black grills, which is what a lot of people choose. You must as well or you wouldn't have got them. They are also the same grills that are on the 128i and the 1M, so that means only the 135i came stock with the all chrome grills.

I also switched back to mu stock 128i kidney grills. I like it better.

[Gangplank]

Yep. I've always liked them better - especially on space gray metallic and blue. The all black only look better on a black or white car and even then it's a matter of opinion.

[PDXE82]

Originally Posted by Gangplank

The all black only look better on a black or white car and even then it's a matter of opinion.

That's my opinion. Chrome on white just doesn't look right to me. I think it's the lack of contrast.

[bm996tt]

I believe the is grills are a nice compromise, picks up the hood emblem chrome while not over doing it. All just personal preference.

[swagon]

Originally Posted by PDXE82

That's my opinion. Chrome on white just doesn't look right to me. I think it's the lack of contrast.

Eh, white with chrome is good. The issue is orange or green.

Black kidneys are the basic bitch mod of the BMW world, anyway.

#chromekidneysmovement

[PDXE82]

Originally Posted by swagon

Eh, white with chrome is good. The issue is orange or green.

Black kidneys are the basic bitch mod of the BMW world, anyway.

#chromekidneysmovement

Well then I'm full on basic bitch! I think that was the first thing I changed as far as appearance.