true posi

[johnnyvee]

about to do some serious changes to the motor, had a question on how to get true posi? Is there a kit someone sells or what

[evilC]

The best limited slip diff is the Quaife Torsen (ATB) unit. There were/are some ZF units still about but IMO the Torsen unit is much more durable and gives a softer take up that is more controllable in less experienced hands. Porsche on the other hand preferred to use the ZF plate diff on their 934/5 racers for a more positive lock up but then they eventually ran fully welded diffs!

http://www.quaife.co.uk/shop_categor...tegory_id/1274

Clive

[vdubzack]

BSI Racing Ormond Beach, FL (386) 677-5778 give them a call and they can steer you in the righ direction.

[vdubzack]

be warned good ones can cost. if you are lucky you can some times find them on ebay for less I personally like Quaife because they will even waranty them if used for racing.

[gonebuggy]

First off, read up on the different types of "posis" There are many types. Mainly the "limited slip"(LSD) and the "torque biasing" They have different advantages and disadvantages depending on application as well.

I personally LOVE my ZF LSD, although I've never run a torque biasing type,

Alex

[johnnyvee]

Excellent information, so the ZF sounds like a hard locking diff. Thats what i want

[gonebuggy]

I never would of imagined the difference it would make on my car, but it's easily one of the best upgrades for our cars. The way the car hooks powering out of turns is just awesome. It sure helps with launches too.

Be warned though, make sure the rest of your drive train is up to snuff. It will make any weaknesses in the system apparent.

My setup with a torquey 2L, built-up IRS trans with type 2 CV's is (so far) near bulletproof and a wicked fun street toy. She'll hook when you want it too, or she'll slide when you want it to.

If you get a ZF take it apart an check the clutches and the thrust washers. The clutches usually last forever, but the thrust washers can wear pretty bad.

Alex

[evilC]

Originally Posted by gonebuggy

.......................
If you get a ZF take it apart an check the clutches and the thrust washers. The clutches usually last forever, but the thrust washers can wear pretty bad.

Alex

That's one of the reasons the Quaife ATB looks so good. Once set it can't really change unless the gear set wears out - and when did you last have a gearset actually wear out? THe Quaife unit is also a 4 pinion diff IIRC, which is a pretty tough unit.
The ZF lsd in my Merc has worn out and requires a (expensive) refurb and I have discussed with Quaife whether they would build an ATB for it.

Clive

[gonebuggy]

Originally Posted by evilC

That's one of the reasons the Quaife ATB looks so good. Once set it can't really change unless the gear set wears out - and when did you last have a gearset actually wear out? THe Quaife unit is also a 4 pinion diff IIRC, which is a pretty tough unit.
The ZF lsd in my Merc has worn out and requires a (expensive) refurb and I have discussed with Quaife whether they would build an ATB for it.

Clive

Parts wearing out can be a design/materials issue or maintenance/install issue.

ATB and LSD are two VERY different animals in function.

Alex

[evilC]

Originally Posted by gonebuggy

Parts wearing out can be a design/materials issue or maintenance/install issue.

ATB and LSD are two VERY different animals in function.

Alex

I agree. the point I was making is that the ZF lsd is a clutch plate design that by its nature has 'consumable' internals (the clutch plates) that have a limited life expectancy, whereas the ATB being a gear design is inherantly longer lasting. The Quaife units have an enviable reputation for strength in other applications that is almost a byproduct of their 4 pinion design

(Sales pitch over)

Clive

[Steve C]

Hi

I had a Quaife in my old 1302, through my own stupidity I broke an output shaft, I was using the type with Type 1 output shafts, you can get them with Type 2 output shafts these are much stronger.

I got stopped by a start line official on my drive up to the start line, when he waved me forward I thought I was in the water burnout area, but I wasn't.

I loved my Quaife.

Steve

[Bugorsh]

I had the internals on my ZF cryo treated, supposed to last 4-6 times as long as non treated. We'll see when I get it installed and put some HP to it.