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Does anyone know where can I get such a thing? Or if something like that even exists for our Alfas.
I've been searching for some time now, but had no luck. I reckon the closest thing is to get some Audi A4/6 LSD as they share the same torsen central unit and the drive shaft must be similar (or at least close enough).
 

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Hi
I have done that several months ago.
I am driving this car on a daily basis. I can get it manufactured for you but it will take at least 1 mth of waiting, this is custom work.
Pictures below. This one is normal 1-way Torsen 2, we can also make a 2-way friction-plate version, it is ~15% more expensive and requires friction plate maintenance from time to time, but it also helps you on deceleration. Depends what you wish :)
More info here: http://alfaclub.ro/forum/viewtopic.php?f=20&t=22062 You are from Romania, you can contact me on that forum.
We already have the blueprints for Crosswagon Q4 (so we can start doing it immediately). For 159 you will have to supply your rear diff for measurements, it will take ~1 week since it is sent abroad. Or you can supply a spare one. Happened the same in my case.
If we work with spare one, then there is a high probability your pinion/crown gear on rear will need readjustment, this is dangerous territory since it requires lots of testing and listening for gear whinning and can result in destroying of the gearing (~1000 EUR :( - happened to me).
Car handling is dramatically improved on slippery surfaces and on taking hard turns, rear of the car feels "sticky". Basically car cuts corners brilliantly with throttle on. I also have a simple stage 1 remap @ 185HP. A BMW 330xd could not keep up with this car on mountain road...
BIG FAT WARNING: since it's a Torsen 2 unit, no grip on both rear wheels means zero traction and zero transmitted torque. You have to adjust your driving skills and take that into account.
 

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For your car it is possible but it is not easy, this assumes you will have to send me your rear diff for measurements (will take 3-5 working days from date that I receive it) + 50% cash advance. After that you can have the diff back and manufacturing takes ~1 mth + shipping time.
You need also a good mechanic to take it out + back.
Or better wait for someone closer to me to do it for 159 and then you will skip the no-diff time. But then you will need also a good mechanic to fit the crown/pinion pair (crush sleeve, spacer rings etc).
I took a look on EPER and the contents of diff boxes of 159 is not documented. Therefore I cannot indicate part numbers for these components. Caveat emptor!
 

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there are other considerations when using Limited slip diffs which often get overlooked especially for torsen style rear diffs. For every 1 Nm torque transferred from one side to the other, the diff also usurps 1 in friction and thus extra heat. there are extra wheels so the diff will typically run slightly hotter anyway.

to make a long story short, you need to change the diff oil much more frequently, and can't go by manufacturers recommendations.

Otherwise, it's all good :)
 

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OK.

So, may be there is any other car that uses LSD in rear diff and may be it will fit my car?
Is that possible?

I have one more question...
How do you assemble that LSD diff? Or you only make some details that must be added to stock open diff and it will beckame like LSD diff?
 

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there are other considerations when using Limited slip diffs which often get overlooked especially for torsen style rear diffs. For every 1 Nm torque transferred from one side to the other, the diff also usurps 1 in friction and thus extra heat. there are extra wheels so the diff will typically run slightly hotter anyway.

to make a long story short, you need to change the diff oil much more frequently, and can't go by manufacturers recommendations.

Otherwise, it's all good :)
Lubrication is another thing, yes, I am using now Motul LSD oil in the rear diff + Metabond additive to minimize frictions.


OK.

So, may be there is any other car that uses LSD in rear diff and may be it will fit my car?
Is that possible?

I have one more question...
How do you assemble that LSD diff? Or you only make some details that must be added to stock open diff and it will beckame like LSD diff?
The only car that uses that rear diff is Alfa Romeo 159/Brera Q4, same version for 3.2V6 or 2.4 JTDm. You will not find it on other car.

The LSD is done from scratch and has nothing to share with the stock open diff. You can keep the stock diff after as an amulet or paperholder :)

What I would do if I were you (because I did the same) is to find another 159/Brera Q4 that is wrecked, buy the whole diff case, take out the diff inside and send it for measurements, receive the new diff, put it into the case, check for correct backlash/play, put proper oil and start testing it. If something goes wrong you have the original case+diff (replacing process is pretty straightforward, takes about 20-30 minutes for swapping cases).

It ain't cheap, but makes a difference especially when taking turns. Audi Quattro or BMW Xdrive will be a bad joke, handling will be close to Impreza WRX or Lancer Evos.
 

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Many thanks.

So you are offering TORSEN 2 right?
There is also TORSEN 3 and what about that? Can you do it?

What about prices?
Where are you located?
 

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AFAIK T3 is only inter-axle since it has variable split torque.
T1 is used only in sport applications and has lower tolerances is noisy and not quite suited for street use.
What I have is street Torsen, Quaife-like.
Torsen - Wikipedia, the free encyclopedia
:)
I am in Romania, please check link on my first post.
 

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As we have an Alfa GT Q4...how much will be the rear diff? and how long it will take you to manufacture it?
 

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I forgot to mention that LSDs are not for free, but considerable cheaper than Quaife. Of course in some Eastern countries this may not be cheap either, but this is life.
 

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I talked at quaife and they said that they need a rear differential for measurements and to tell if they can make a rear lsd for the car, and after that they would tell the price
it would be better if we could get at least a 30 units order.
Is someone interested?
 

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Firstly we will need to take a normal rear differential to Quaife for measurements, so they could tell us if they cand make it
and than they will tell us if they cand make it, the price and if it would be needed a minimal order
someone in uk willing to sacrifice a rear diff for a few days?
 

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May be we should just collect money and buy one rear diff (even damaged will be good) and send it to Quaife?
I don't think that anyone between us will be able to remove his own diff for this reason.
 

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Firstly we will need to take a normal rear differential to Quaife for measurements, so they could tell us if they cand make it
and than they will tell us if they cand make it, the price and if it would be needed a minimal order
someone in uk willing to sacrifice a rear diff for a few days?
The Q4 was never offered for sale in the UK, I've only ever seen one here but it was on French plates so could have been a tourist car. You'll be lucky to find someone in the UK who has one.
 
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