Anyone used a quaife ATB diff ?

Mon Sep 03, 2007 5:28 pm

http://www.quaife.co.uk/BMW-325i-E30-E3 ... fferential

are they any good ?

Mon Sep 03, 2007 5:30 pm

I think Birds are the new distributors for Quaiffe diffs in the UK.

They may even make some OEM diffs for BMW but don't quote me.

Mon Sep 03, 2007 5:38 pm

they are not true LSD's though, they dont lock up 100%????????

Mon Sep 03, 2007 7:25 pm

you can mod a BMW LSDs lock though

Mon Sep 03, 2007 7:52 pm

m-dtech wrote:they are not true LSD's though, they dont lock up 100%????????

Even e30 LSD's only lock up 25% thats where the "limited slip" bit comes in-they allow slip before locking

Mon Sep 03, 2007 7:55 pm

320Touring wrote:
m-dtech wrote:they are not true LSD's though, they dont lock up 100%????????
Even e30 LSD's only lock up 25% thats where the "limited slip" bit comes in-they allow slip before locking

yes i know that, but according to quaife their diff does not lock up at all

Mon Sep 03, 2007 8:04 pm

m-dtech wrote:
320Touring wrote:
m-dtech wrote:they are not true LSD's though, they dont lock up 100%????????
Even e30 LSD's only lock up 25% thats where the "limited slip" bit comes in-they allow slip before locking
yes i know that, but according to quaife their diff does not lock up at all

So i see- seems like some kind of gear transfer to the opposite wheel...

Tue Sep 04, 2007 12:53 am

In my experience of using the quaife diff ...... you get some spin on the inside wheel before it grabs or locks. This is unsatisfactory and I don't believe it can be modified to eliminate this unfortunate trait. Of course a well sorted car with effective suspension will do this less than a poorly prepped car.

The BMW LSD on the other hand .... while it may well be that many of them have lost their grip through many road miles ..... they can be retrieved to as new condition and with shimming and ramping and using extra plates they can be modified to lock up extremely tightly. You can use the Ford Atlas LSD plates for this purpose.

Tue Sep 04, 2007 7:49 am

i believe the nature of the quaife means that its great on track, but not so good for 'drifting' and the like..

Tue Sep 04, 2007 12:42 pm

does anyone here use one ?

Thu Sep 06, 2007 7:41 pm

They snatch like hell in a Westy!
But they dont half work.. they seem to let the car drift a bit and then grab it.. and the more stick you give it the better it works.
Personally I feel a light car like a Westfield does not need one and is smoother to drive on an open diff.

If you are into sprints and hillclimbs, fair enough.. but otherwise save your money.

Thu Sep 06, 2007 11:52 pm

its part and parcel with the kit i have bought on the westfield.

i was thinking more for comparison to bmw e30 diffs as i think they can be bought new for the same price as second hand ones go here.

Fri Sep 07, 2007 7:43 pm

Don't know about them in BMW's.. sorry!

But when you feel the need for more ooomph from your 'Busa let me know.

Nick

Thu Sep 13, 2007 1:20 pm

Not a clue how good they are on an E30 but my friend has one fitted to his Toyota starlet Gt turbo and my god does it perform. Theres so much more grip and handling is perfect i highly recommend them after seeing wat they can do on a fwd car.

Depends wat ur looking for if its a track car id say it would work perfect but if your looking for a drift E30 theres other diffs which wud perform alot better for that purpose, Have u seen the kaaz 1.5 way LSD-

Its for sale here on driftworks-
http://www.driftworks.com/catalog/produ ... d-bmw.html

Sun Sep 30, 2007 12:22 am

Might be tempted by one of these, but i'll have to find out some more info though!!!!

If they really are the same price as a used or rebuilt bmw diff, i'll prob be tempted into trying one out!!!

Won't be until Nov probably, but i might give them a ring and see what they say!!

One of the track day instructors at brands was telling me that he was doing testing for birds on some of the new E30 quaiff stuff and he was impressed!!!

Mon Oct 01, 2007 11:08 pm

you dont technicaly want your wheels to lock though, you want the power to get down and keep momentum to the maximum limit.

i presume that the quaife diff keeps the power down and if you do loose it, the diff locks and handles like an LSD allowing you more control of a slide unlike an open diff ?

Wed Oct 03, 2007 12:05 am

The Quaife diff is a TorSen (torque sensing) unit. These have been around for some time now, and they do work within their limitations. The biggest of these is that they don't actually lock up; they just limit the difference in torque applied to each wheel. This is expressed as a ratio, typically 1:10 or 10%. This means that the spinning wheel can have a tenth of the applied torque that the gripping wheel has. On dry tarmac it's quite hard to spin a wheel that's on the ground, so they behave much like an open diff in that the wheels can still turn at different speeds, but the torque transfer mechanism prevents one wheel from spinning up by itself.
They're widely used on FWD cars, where a conventional LSD would cause massive understeer.
Problems occur when you treat a TorSen like a regular LSD, because it isn't one

If one wheel has no grip and hence no torque can be applied (say it's off the ground or on ice), the other can only get 10x that..... which is still no torque, so it will behave like an open diff.
A RWD car with one of these units would probably be quite driftable in the dry, but the difference in grip between a spinning and a gripping wheel in the wet is likely to be more than it could handle, resulting in in behaving like an open diff.

Wed Oct 03, 2007 12:37 am

so these diffs are ideal upgrade to those who want to race or want to keep maximum traction.

BMW LSD = Drifting / Rally

Quaife TorSen = Racing, 1/4 mile etc