All this differential talk has me thinking (335i)

[Ryan Mills]

Are the guts of the 335i differential the same size as other BMW models? For example, it LOOKS like the E39 540i diff and the Z8 Diff use the same quaife unit, so the ring/pinion and carrier might be the same size, right? This would make it easier to find a bolted unit to get a quaife for, or it might make it possible to use a factory LSD swapped into the 335 case. Thoughts?

[DBFIU]

We need some of our experienced vendors in here to answer this question.

[Sorena]

You can swap the 335i's diff with M3, i'm aware of this. But not sure about others

[Ryan Mills]

So that is one option, but I would be interested in a more popular model, maybe older to see if I can snatch a whole diff for $250. At that price, it's almost cheap enough for me to pick up another model diff and an extra 335i rear and see what I can come up with. I'll look into this as the weather gets warmer and hopefully find a cheap solution.

[Sticky]

See what @George Smooth has to say.

[George@BMS]

We need some of our experienced vendors in here to answer this question.

I think the vendors might not give out information. Especially the ones that sell LSD's. The main reason I fitted a M3 diff is because two of them told me its impossible. The one said its easier to land on the moon hehehe proved them wrong.

[George@BMS]

You can swap the 335i's diff with M3, i'm aware of this. But not sure about others

Is this confirmed as fact or did someone just say this?

[George@BMS]

So that is one option, but I would be interested in a more popular model, maybe older to see if I can snatch a whole diff for $250. At that price, it's almost cheap enough for me to pick up another model diff and an extra 335i rear and see what I can come up with. I'll look into this as the weather gets warmer and hopefully find a cheap solution.

As far as I know I do not think its possible. If you look at Diffsonline website and from what I have communicated its not possible. They only offer the two ratios (manual and auto) for our diffs which means none of the other ratios are interchangable. I will ask my tuner tonight for further opinion.

[Sorena]

Is this confirmed as fact or did someone just say this?

lol, someone in South Africa has done it. Maybe you know him?

[George@BMS]

lol, someone in South Africa has done it. Maybe you know him?

I will check, we do not get something local to us called the is so it must just be a coupe DCT N54 or N55. There is one that parks five meters from me so will climb under and see if it will work.

[Ryan Mills]

I will check, we do not get something local to us called the is so it must just be a coupe DCT N54 or N55. There is one that parks five meters from me so will climb under and see if it will work.

I appreciate the effort! I'm tempted to buy a used rear on ebay just to have one in my hand to compare, but it is an expensive experiment.

[dzenno@PTF]

I appreciate the effort! I'm tempted to buy a used rear on ebay just to have one in my hand to compare, but it is an expensive experiment.

More often than not that's the only way to get things done

[_Ryan_]

So I had this post on the other site:

---------------------

Which other cars use the "bolted small pumpkin" unit? For example, KAAZ do not list a part for the 135i automatic (which shares it's diff with the 130i), although they list a plethora of other models, now if one were to be interchangable...

BMW
MODEL ENGINE GRADE YEAR M/T POSITION NORMAL L.S.D. PLATES PLATE 1.5WAY REMARKS
TYPE SIZE CAM
3 series
E30 6－cyl 325i 85~90 MT/AT REAR OPEN BASIC 12 M DBW3010
4－cyl M3 MT/AT REAR Mechanical BASIC 12 M DBW3010
4－cyl 318is 89~90 MT/AT REAR OPEN BASIC 12 S DBW1810
E36 4－cyl 318is 93~98 MT/AT REAR OPEN BASIC 12 S DBW1810
4－cyl 318ti MT/AT REAR OPEN BASIC 12 S DBW1810
6－cyl M3(3.0) 93~95 MT/AT REAR Mechanical BASIC 12 M DBW3010
E46 6－cyl 328 MT/AT REAR OPEN BASIC 12 M DBW3020
E46 6－cyl M3 MT/AT REAR OPEN BASIC 12 M DBW3020 M1
5 series
E28 6－cyl 525i、535i 81~88 MT/AT REAR OPEN BASIC 12 M DBW3010
E34 6－cyl 525i、535i 88~95 MT/AT REAR OPEN BASIC 12 M DBW3010
Z series
4－cyl Z3Roadster1.8 96~ MT/AT REAR OPEN BASIC 12 S DBW1810
4－cyl Z3Roadster1.9 MT/AT REAR OPEN BASIC 12 S DBW1810
6－cyl Z3Roadster2.8 97~ MT/AT REAR OPEN BASIC 12 M DBW3010

from kaazusa DOT com/lsd_bmw.html


----------------------

But then did further research and it looks like this KAAZ part should fit: KAAZ LSD Basic 1.5way for BMW (DBW3020)
Just not quite sure if I want to take a 2k (installed) gamble at the moment.

The other concern- for a weekender/track car or track only car, a clutch pack mechanical LSD makes perfect sense, but for a daily driven car, I am unsure whether this will confuse (ie; require disabling of) DSC/TC. I believe the torsen style LSD such as a Quaife will not present the same issues when working WITH the factory electrics.

(background, I live on a mountain where the roads are wet 70% of the time, although I have owned far higher powered cars without the 'aids' that the BMW provides, i tend to leave them on in poor conditions)

Thoughts?

[DavidV]

A Quaife or Wavetrack performs very well on a track, and is an awesome asset for daily use.
It will bring a smile on your face, guaranteed.
And it is not too tricky in wet and slippery conditions, as the LSD works with the electronics in the car.
It's just the electronics have less to do. And because of the nature of the torsen style LSD they are not as snappy as a clutch style LSD can be.
As long as you're not building a 100% track only car you're good with a torsen style LSD.
If you are going beserk style on drifting/track I would suggest a cooling backplate for the diff assembly though.

[_Ryan_]

A Quaife or Wavetrack performs very well on a track, and is an awesome asset for daily use.
It will bring a smile on your face, guaranteed.
And it is not too tricky in wet and slippery conditions, as the LSD works with the electronics in the car.
It's just the electronics have less to do. And because of the nature of the torsen style LSD they are not as snappy as a clutch style LSD can be.
As long as you're not building a 100% track only car you're good with a torsen style LSD.
If you are going beserk style on drifting/track I would suggest a cooling backplate for the diff assembly though.

Thanks David, have you any experience drifting with a Torsen LSD? I've only used clutch packs.

[DavidV]

I have had a Quaife in my 135i for almost 3 years now, so yes
The LSD comes in with a little delay, and can hold up to 80% lock, which is more than enough.
Because of the small delay it takes a little more work to engage a drift, whereas the clutch type kicks in immediately.
Once you're used to a torsen LSD you don't have to think about what to do when you want to drift.
For day to day use it is less nervous to drive than a clutch LSD when conditions are more challenging.

[TRES]

i agree with david I also have a wavetrac lsd and performs flawless on the track and the street. I 've had it since 2011 and no issues. Also you can fit an M3 diff on a n54 it has been done already

[_Ryan_]

I have had a Quaife in my 135i for almost 3 years now, so yes
The LSD comes in with a little delay, and can hold up to 80% lock, which is more than enough.
Because of the small delay it takes a little more work to engage a drift, whereas the clutch type kicks in immediately.
Once you're used to a torsen LSD you don't have to think about what to do when you want to drift.
For day to day use it is less nervous to drive than a clutch LSD when conditions are more challenging.

I'm revisiting this at the moment as MFactory have released a KAAZ competitor and I've had other priorities.

I presume the clutch LSD will fight the electrics?
How do you find your Quaife on wet/icey roads, or hard pack unsealed roads?

[mjmarovi]

I'm revisiting this at the moment as MFactory have released a KAAZ competitor and I've had other priorities.

I presume the clutch LSD will fight the electrics?
How do you find your Quaife on wet/icey roads, or hard pack unsealed roads?

I had looked into swapping the M3 rear diff when I was looking for an LSD and it seemed the easiest way to do it was to find the whole pumpkin and do a half shaft and drive shaft swap as well. Not as bad as it sounds since our cars come with a 2 piece driveshaft and it's probably a good idea to upgrade to a one piece anyway from DSS or something.

[DavidV]

I presume the clutch LSD will fight the electrics?
How do you find your Quaife on wet/icey roads, or hard pack unsealed roads?

If you do not disable the traction control (only the first step is enough), in tricky situations the ESP can jolt the back around because the electronics counter reacts the LSD's input.
You'll get used to that (strangely only happens on wet roads going uphill), or do as I do, and disable traction control and enjoy the LSD more (hail to the JB4 option which disables this for me automatically!). That will make the car a lot more predictable.

I uderstand the reason for your last question, but for me the Quaife has never let me standing in slippery conditions
In winter conditions I have winter tires so I never encountered a situation where I had no traction at all on one wheel.
In fact having a LSD in snow is quite fun.
And it is a moot point anyway, because if you ever find yourself on a tight uphill turn where one rear wheel is off the ground, you just make some friction to the wheel that's off the ground by pulling your handbrake slightly and you will get out of that sitiation with a Torsen diff.
I would not worry about that at all.
There has to be absolutely zero grip to even consider that trick.
In 3.5 years with my Quaife it has never happened to me yet.

[_Ryan_]

If you do not disable the traction control (only the first step is enough), in tricky situations the ESP can jolt the back around because the electronics counter reacts the LSD's input.
You'll get used to that (strangely only happens on wet roads going uphill), or do as I do, and disable traction control and enjoy the LSD more (hail to the JB4 option which disables this for me automatically!). That will make the car a lot more predictable.

I uderstand the reason for your last question, but for me the Quaife has never let me standing in slippery conditions
In winter conditions I have winter tires so I never encountered a situation where I had no traction at all on one wheel.
In fact having a LSD in snow is quite fun.
And it is a moot point anyway, because if you ever find yourself on a tight uphill turn where one rear wheel is off the ground, you just make some friction to the wheel that's off the ground by pulling your handbrake slightly and you will get out of that sitiation with a Torsen diff.
I would not worry about that at all.
There has to be absolutely zero grip to even consider that trick.
In 3.5 years with my Quaife it has never happened to me yet.

Thank you for the response. It appears that a Quaife will meet my requirements.
I have experience similar events when the car has stepped out and I have corrected as the ESC/ESP has kicked in- safer and more predictable with it all turned off (for me having grown up on RWD cars).

[DavidV]

If you only disable traction control the ESP will be your safety net no matter what you do.
Even on track days I normally leave this option on if the track is slightly damp or I spot cars with leak oil on track.
That has prevented me from spinning off on various occasions while keeping things reasonably safe and fun, and still have an acceptable slide angle to still feel playful.