Quaife LSD Anyone interested?

[DKZTT]

I wrote to Mike at Vac about a week ago and finally got a reply. Would anyone be interested in a group buy if I can get them to do one for Z4 owners? You can buy the lsd and take it to a local machine shop and have it done, but who knows if you will get it done right. Anyway below is the reply I received from Mike.

"$1400 for the Quaife ATB. We charge $2575 + core for the 135/335i guys and your diff is essentially the same, just with a different core dimension. Internally they are the same. Are you familiar with the build process? It’s quite a bear:
http://www.vacmotorsports.com/blog/v...-how-we-do-it/ "

[jparnes1]

I was interested in your thread topic, but then I read the text.

[DKZTT]

Originally Posted by jparnes1

I was interested in your thread topic, but then I read the text.

Ok I edited the title, no one should be confused and get all excited about the other LSD.

[army_men]

I went on a car forum and all we talked about was cats, meth and lsd. sometimes even DP!

[Brian_VACsales]

Originally Posted by DKZTT

I wrote to Mike at Vac about a week ago and finally got a reply.

The email was in my SPAM folder, sorry.

Most machine shops are not set up to do this job...let alone properly. We have done 100s on our very expensive CNC equipmnent so we have it mastered :-)

Our everyday price is $2575 + core. That is the best price from any vendor.

If we can get at least 5 sales on a group buy I will discount it 10% :-)

Some good info:
http://www.vacmotorsports.com/blog/v...-how-we-do-it/

http://www.vacmotorsports.com/blog/3...no-lsd-really/

[DKZTT]

Originally Posted by army_men

I went on a car forum and all we talked about was cats, meth and lsd. sometimes even DP!

A little off tangent, but maybe you guys were on meth for the high, lsd for the next dimension, and there you saw the same damn black cat passing by in front of you.

Anyway, how many of us here are on aftermarket tunes and can't put the power to the wheels to the pavement? I am seriously considering this since I am spinning my tires after the Cobb stage 2 tune.

[Asbjorn]

I don't have traction problems when warmed up and going straight on better roads. What tires do you use?

On corners it is easy to loose grip, but then i often want it to!

I would only miss an LSD if i were to do drifting at a higher level. It may also introduce more understeer.

[DKZTT]

Originally Posted by Asbjorn

I don't have traction problems when warmed up and going straight on better roads. What tires do you use?

I just put on new wheels and PSS. I spin my wheels in 1st from a stop if I step on it a bit, not even flooring it and when I'm cruising around 40 and step the pedal maybe half way, it spins too. Driving done on good roads.

[Bob20124]

DKZTT
I sent you a PM
Bob

[Hujan]

So the Quaife is $1400 but a custom built VAC one is $2575 plus core?

[nicknaz]

I THINK our diffs along with later 335 and 135 are welded to the frame so it is a huge bear to install the LSD

OP, I'm not as far down the E89 path as you, so I'm going to take a pass and will just switch the car next year for one with LSD and appropriate weight/power levels from factory....

[Lambobimmer]

When I had a 135i I did this and it is not really worth it unless you are building a track car. Spend your $2,500 on coilovers or something else.

I did it the cheap way though. I found a donor diff from a 2007 335i which had a bolted ring. Bought a Quaife LSD and had my friend (who works for BMW) put it together. I got out really cheap and I actually made a few $100 when I parted out my car. It is much cheaper and easier if you can find a donor diff that has a bolted ring. I had a total of $2,111 in my diff which included a donor diff shipped from NY, labor to remove my old diff and replace it with newly built Quaife Diff. The total was $1,711 in parts and $400 in Labor.

There is nothing special about putting together a diff unless you are changing the R&P and then you really need an expert in diff work.

Also, I believe that all of the diffs on the DCT are bolted so no machine work should be necessary. I might be wrong on this but I believe that this is the case.

I am sure that VAC does great work and I have nothing against them but I thought that I would share my story.

Save your money guys.

[HerrK]

Originally Posted by Lambobimmer

When I had a 135i I did this and it is not really worth it unless you are building a track car. Spend your $2,500 on coilovers or something else. Save you money guys.

I agree with you on the bang for the buck effect. Either route is more than I'm willing to spend. That money would make a great down payment on a twist of the wrist two wheeled roadster - 160 bhp, 83 lb/ft torque, power-to-weight ratio of 2.85 pounds per bhp, race ABS and ASC.

Light em up fun! - BMW S1000RR

[Brian_VACsales]

E89 final drives are different dimensionally than the 135/335 final drives, so a bolted 2007 335i unit will not bolt in an E89.

All DCT diffs are welded.

I'm not trying to shamelessly hock stuff, but as an enthusiast I must note that pretty much every performance car has an LSD for good reason. (lets not talk about the P1 ;-)

Both of my RWD cars have LSDs (M-Variable / TRD multi-plate) and my last daily also had one stock (6MT TL) I haven't daily driven a car without LSD since 2001!

Quaife ATB is $1400. Parts and labor to install is $1175. Click the link above to see what goes into this job ;-)

Originally Posted by Lambobimmer

I did it the cheap way though. I found a donor diff from a 2007 335i which had a bolted ring. Bought a Quaife LSD and had my friend (who works for BMW) put it together. I got out really cheap and I actually made a few $100 when I parted out my car. It is much cheaper and easier if you can find a donor diff that has a bolted ring. I had a total of $2,111 in my diff which included a donor diff shipped from NY, labor to remove my old diff and replace it with newly built Quaife Diff. The total was $1,711 in parts and $400 in Labor.

There is nothing special about putting together a diff unless you are changing the R&P and then you really need an expert in diff work.

Also, I believe that all of the diffs on the DCT are bolted so no machine work should be necessary. I might be wrong on this but I believe that this is the case.

I am sure that VAC does great work and I have nothing against them but I thought that I would share my story.

Save your money guys.

[Asbjorn]

Originally Posted by DKZTT

I just put on new wheels and PSS. I spin my wheels in 1st from a stop if I step on it a bit, not even flooring it and when I'm cruising around 40 and step the pedal maybe half way, it spins too. Driving done on good roads.

I never step on mine from a stop because I worry about the clutch

Other than that, I think your PSS tires will reach their optimum performance only after they have been broken in properly. Also the temperature makes a big difference. Make sure your tire pressure is correct as well. Other than that, putting on wider tires seems like the cheapest solution. With all the mods you have listed, you ought to target M5 size tires. But maybe you are already close?

In my view, you only need an LSD if want to spend lots of time spinning the wheels and going sideways. But you just have to realize there is a reason the LSDs are electronic in M cars...

Anyway, in my dreams, my Zed looses its roof entirely to save weight and wears 9J rear wheels with 245 all-weather tires and an LSD. In that dream there would also be a track where I can spend all day drifting near my home.

[Brian_VACsales]

Originally Posted by Asbjorn

In my view, you only need an LSD if want to spend lots of time spinning the wheels and going sideways. But you just have to realize there is a reason the LSDs are electronic in M cars..

They are mechanical in M cars.

Nothing like the fugazi 'e diff' in the N54 cars....which is just an open diff with some computer controlled braking scheme.

[Bob20124]

I'm in.

[Hujan]

Originally Posted by Mike@VAC

They are mechanical in M cars.

Nothing like the fugazi 'e diff'in the N54 cars....which is just an open diff with some computer controlled braking scheme.

[Asbjorn]

Originally Posted by Mike@VAC

They are mechanical in M cars.

Nothing like the fugazi 'e diff' in the N54 cars....which is just an open diff with some computer controlled braking scheme.

They used to be mechanical, but now they are electronic, read more here:

http://www.bmw.com/com/en/newvehicle..._catalogue.pdf

Quote: "How does the Active M Differential work? It adjusts electronically and in advance. The previous system only locked with wheel spin on the rear axle. Now we can steer the lock proactively. An electronic control unit links the active system and DSC. If the accelerator is engaged and the sensors anticipate wheel spin, locking torque is applied to the differential. This prevents wheel spin, power is optimally transferred to the tarmac and the driving situation is dynamically controlled."

The diff in N54 cars are all mechanical, also the one in the 1-series M coupe.

Quote: "The BMW 1 Series M Coupe is fitted as standard with a variable M differential lock. This generates lock-up torque as required and completely variably up to 100%, thus providing for optimum traction on all road surfaces. The variable M differential lock responds to differences in rotational speeds in the right and left rear wheel, redirecting drive torque within a fraction of a second. So where there are significant differences in friction coefficients between the right and left rear wheel, for example, optimum traction and maximum propulsion power are ensured. The principle of the engine-speed-sensing M differential lock supports the dynamic qualities of rear-wheel drive both on slippery surfaces and when accelerating out of bends."

The e-diff you refer to is a DSC sub-function which according to speculation is only active in DSC=off mode (ie not in DTC mode), and only on cars fitted with open non-variable differentials. According to speculation it is configured more aggressively on the Z4 compared to N54 3-series cars.

In any case, it prevents the situation where only one wheel keeps spinning, although the diff is open. The upside is price, also on maintenance, and the downside is that the system does not react instantly as with the variable locking mechanical diffs, or proactively as is possible with the electronic locking diffs.

[jannisa]

All N54 Z4s manual or dct have welded crown. N52 23i and 30i are bolted.

Your safest route would be to get a complete modified pumpkin by vac, hp, birds and return your core diff for a refund. I had problems with birds uk for months as the pumpkin they originally delivered was producing a whining noise around 70-120 km/h and Kevin Birds was practicing a rather annoying attitude like it was anything but their unit or the installation of the pumpkin the cause. He never covered the additional cost of 700 euros I had to bear for adjusting twice the preload of the pinion, opening the diff to check the backlash - all this per his instructions, paying again for another 2 way delivery for a new pumpkin and return of the core to his shop and of course the additional installation. I had to pay again for the second unit obviously and I would get the refund once they examined the first pumpkin in order for them to determine the cause of the issue. 10 days after they received it Sherlock responded that the problem was indeed a defect ring-pinion pattern. They blamed BMW and didn't even apologize.

The verdict is that the quaife lsd offers a huge amount of grip with all dsc/dtc off and works great in combination with the factory e-diff. You won't see much difference if trying to powerslide or drift as atb diffs will fight against you to regain grip, you would need a clutch type lsd for that matter.

If you find yourself constantly switching all traction controls off and flooring it then go for it. In retrospect I wouldn't buy it, I would keep my car stock and spend mods money to buy a black manual e46 M3 coupe and have the perfect stable.

[DKZTT]

Originally Posted by Asbjorn

With all the mods you have listed, you ought to target M5 size tires. But maybe you are already close?

I currently have 19x8.5 with 235/35 fronts and 19x9 with 265/30 rear. I have the adjustable sport suspensions and almost always drive in sport mode. I am looking at options(quaife vs wavetrac) and went to the 335 forum researching since they would have more experience with the pros and cons with this type of mod. Found on the 335 forum there is a company DiffOnline and you can order custom diffs with many options from clutch type to lsd (quaife, wavetrac). Due diligence research before I plunk down $4k+ for this mod.

[nicknaz]

Originally Posted by jannisa

All N54 Z4s manual or dct have welded crown. N52 23i and 30i are bolted.

Your safest route would be to get a complete modified pumpkin by vac, hp, birds and return your core diff for a refund. I had problems with birds uk for months as the pumpkin they originally delivered was producing a whining noise around 70-120 km/h and Kevin Birds was practicing a rather annoying attitude like it was anything but their unit or the installation of the pumpkin the cause. He never covered the additional cost of 700 euros I had to bear for adjusting twice the preload of the pinion, opening the diff to check the backlash - all this per his instructions, paying again for another 2 way delivery for a new pumpkin and return of the core to his shop and of course the additional installation. I had to pay again for the second unit obviously and I would get the refund once they examined the first pumpkin in order for them to determine the cause of the issue. 10 days after they received it Sherlock responded that the problem was indeed a defect ring-pinion pattern. They blamed BMW and didn't even apologize.

The verdict is that the quaife lsd offers a huge amount of grip with all dsc/dtc off and works great in combination with the factory e-diff. You won't see much difference if trying to powerslide or drift as atb diffs will fight against you to regain grip, you would need a clutch type lsd for that matter.

If you find yourself constantly switching all traction controls off and flooring it then go for it. In retrospect I wouldn't buy it, I would keep my car stock and spend mods money to buy a black manual e46 M3 coupe and have the perfect stable.

GREAT post.