Ordered Quaife today

its kinda of steep price but VERY VERY tempting indeed!!!!

It's been raining for days in Atlanta, so the Quaife has gotten a pretty good workout. It makes a dramatic difference in the way DSC behaves. It's obvious the DSC logic is written to accommodate a LSD (or TBD in the case of a Quaife). With the Quaife you can lacceletate rapidly, straight or turning, without DSC engine intervention kicking in until you spin the rears too fast or start to slide. It's much safer to drive as there isn't the virtual stall if you apply a little too much throttle.
The fact that the quaife works so well, and so much better than DSCs automatic brake differential (ABD) has led me to research what the DSC system logic really is. I haven't found it yet, but my seat of the pants take is that in DSC if one wheel spins the first step is to cut torque through engine intervention, if it continues to spin, DSC invokes ABD, If you turn on DTC, by pressing the button, this logic is reversed, ABD is invoked on one wheel spinning and if both wheels spin past the limit (which is higher than the DSC limit) engine intervention kicks in. DSC will allow some wheel spin as long as both wheels are spinning, which is where the Quaife come in, doubling traction and spinning both wheels if too much throttle is applied.

If you live in a snowy/icy climate and are concerned about the Quaife not working with one wheel on ice or off the ground, punch the DSC/DTC button and ABD will brake the spinning wheel and off you go.

Great stuff ChasR. How long did the install on the LSD take and how long did it take for you to get it from VAC after purchasing it?

Ordered it 12-12 and it shipped on 12-28. It was a 2 hour job.

Amigo has your mileage improved or decreased since NOW you can race better LOL

Mileage is unaffected. Tire wear may be affected now that DSC allows some wheelspin. I'm going to have to do a track day soon.

cool!!

@ChasR,
Dumb question but do they reuse your original ring and pinion? I'm wondering if we will be able to keep our final ratio at 2.83:1. This is what gives us the low revs at cruising speed compared to the gassers. Or do we use a new ring and pinion of same ratio? thanks (one gear head to another one )

Nevermnd, i went to their website and got my q's answered. The 2.81:1 ratio is retained. The performance built assy is specific to the 335D. From the description, it sounds like everything inside is redone as the ring and pinion is described as "welded" on their site. This requires special tooling they say.

What lube do they recommend?

Sent from my MB525 using Bimmer App

Redline of some type. I'll find out in a bit. The shop put it in for me. It doesn't have to be LSD specific lube, as there are no clutches or friction plates.

Originally Posted by ChasR

The shop put it in for me.

If you don't mind sharing, which shop did you use? If that's too nosey, just ignore the question.

Wright"s Car Care on Peachtree Road in Atlanta (almost Chamblee) It's owned by a buddy of mine from my BMWCCA club racing days, David D. THe unit from VAC comes assembled, so the in shop job is relatively minor, a chunk swap. Call David if you want to explore your options.

Originally Posted by ChasR

Wright"s Car Care on Peachtree Road in Atlanta (almost Chamblee) It's owned by a buddy of mine from my BMWCCA club racing days, David D. THe unit from VAC comes assembled, so the in shop job is relatively minor, a chunk swap. Call David if you want to explore your options.

How long did the whole process take, since I heard our differentials are welded on?

It took two weeks to fill the order and two hours to do the work. Buy a completed diff, pay the refundable core charge of $900 or so dollars, and send your old differential back to them for a refund after you install built diff.

THe differential housing (chunk) is bolted to the car, the ring gear is welded to the differential carrier, which makes the job more difficult. To install the quaife part the ring gear has to be separated from the old carrier and welded back onto the quaife carrier.

Really, they cut the weld on your original ring gear and and reweld it onto new carrier? For that kind of money, i had presumed they would just use a new ring and pinion and weld the ring on.

Perhaps they do. I would guess it depends on how the ring is welded on. I presume puddle welded, in which case one would drill out the puddle in the old carrier and reweld a new puddle through the quaife carrier. It doesn't say on the website. Either way it increases the cost.

So just to be clear, you receive the entire carrier with ring/pinion already shimmed and set inside so the install is technically a bolt in operation?

Jay

Yes, you recieve the differential fully assembled, ready to bolt in. Installation actually falls into the advanced DIY category (you don't want to drop a 100 lb chunk on your head).

ChasR,

What options are available from VAC in order to ship the LSD? Was the price listed anywhere on the box? I ask because living in Canada, I worry about crazy duty taxes or pathetic USPS brokerage fees when sent via ground shipping.

Thanks!

Originally Posted by GreekboyD

ChasR,

What options are available from VAC in order to ship the LSD? Was the price listed anywhere on the box? I ask because living in Canada, I worry about crazy duty taxes or pathetic USPS brokerage fees when sent via ground shipping.

Thanks!

You should just make a trip out of it. Philly isn't that far of a drive.

Originally Posted by DZLMoose

You should just make a trip out of it. Philly isn't that far of a drive.

I would if I didn't hate driving long distances.

Furthest I'll go, and have gone is Montreal or Ottawa.

Originally Posted by GreekboyD

ChasR,

What options are available from VAC in order to ship the LSD? Was the price listed anywhere on the box? I ask because living in Canada, I worry about crazy duty taxes or pathetic USPS brokerage fees when sent via ground shipping.

Thanks!

VAC shipped it to me UPS ground for $98. I shipped the old one back to them by FedEX ground for $68.00. I know nothing about Canadian duties or tarrifs. Only the weight is listed on the box.

VAC may know what it costs to ship to Canada. Call them.

Thanks again man. That's my best route for sure.

Hey ChasR,

I'm at the VAC website and for the Quaife LSD I see 3 different options:

1) "I will ship my core to you"
2) "Build into good used/low mileage core" (+$900)
3) "Build into brand new core" (+$1400)

Can you explain the differences to me if you don't mind

Thanks.