The guard LSD are very good, however they are $$$ and they use a clutch pack system which requires a lot more maintainance than the gear driven.

I had a quaife in my last car and it was great. That is what I'm hoping to accomplish with the 996, the only issue is the PSM and the rates that the quaife opperate at are not really compatible. The car is mostly a daily driver and some spiritited weekend drives, perhaps the occasional DE so I'm not interested in things like disabling the PSM or a high maintainance clutch pack LSD.

So far it really looks like I'm just going to have to live with PSM unless I win the lottery and get a GT3!

 

Hey, if you are going to install a LSD, let me know. I be interested as well!

 

I had mine done at The Racers Group (located in Cali) when my car was there for the build. Don't remember the price.. but give them a call

 

Yeah, they're up in Petaluma now. I actually was up there a while back with the Carlsen drive. Great group of people. I don't know if I'm ready to fork out the big dollars yet, Andy says the install should be fairly easy and I will like to take a stab at doing it myself if possible.

 

Ah correction, I don't think I said it would be easy. I would require cracking the transmission, possibly resetting the backlash on the ring gear. I don't have experience in that especially in a Porsche where the diff is in the transmission, not at the other end of the car.

Sorry Roger, can't help you with the install.

For now it looks like it will be a mod done later down the road if at all.

 

Sounds way too complicated/expensive for me to want to do in the near future...

 

Doing the LSD install is something you don't want to experiment / learn on. Too many critical measurements for my taste.

I am curious, from an academic standpoint, how the PSM will interfere with the gear driven LSD like the quaife?

 

Sorry for the dumb question here but why don't you just turn off the PSM it is right there on the consul and you can have at it. I personally like having it on it teaches me to drive faster without enabling it

 

Manthey-motors.de in Germany sell LSD for 996 tt. The price with installation is about € 2600. I am sure they can ship worldwide.

 

Call Quaife. I have one on my BMW M5, but no traction control in 1988. Still $1,695 for most any car. Bet they know how to set it up too, or can point you to somebody who does. Don't you imagine somebody at Porsche buys them from Quaife anyway? At those prices, maybe they should.

http://www.quaifeamerica.com/differe.../diff_apps.htm

SC

 

Found this.

http://cgi.ebay.com/ebaymotors/ws/eB...6706727&rd=1,1

The auction is over, but it didn't sell. He may still have it.

 

there is a brand new one up for bid on ebay from guards - $900 buy it now.

http://cgi.ebay.com/ebaymotors/PORSC...QQcmdZViewItem

 

I know this is an old thread but I thought I'd share my limited slip diff expirience .

I heard mixed reviews of geared diffs like the quaif and wave track , but they don't do anything for deceleration like a plated diff does. But geared diffs are great coming off the line and out of corners and they are a cheaper option .

The aftermarket has the guard transmission diff , which by all accounts is fantastic , it's a true clutch plated diff . ( I think they make a geared diff too)

I also checked out the diff as fitted to the 40th anniversary model. It's similar to the gt3 diff but it has 25/27 locking , pretty weak.
The other thing with the 40th diff is it has brass plates and soft clutches , good for about 30-50k miles or two good track days before they need rebuilding according to my Indy . So not sure 5 k from porsche is worth it. If you've a 99 with lsd it's worth jacking the car up and turning the rear wheels to see if it's gone open by now or your clutches are still good.

So I started saving up for the GT diff .
Then one day I saw a 40th diff out of a wrecked car on ebay . I asked guard if it's possible to rebuild it with guard internals which are much more robust than the porsche ones.
Yes was the answer .
So I bought the ebay one for 400 bucks and had it rebuilt with guards steel disks , beefy clutches and 40/60 ramps .

I've installed it in my 2004 c2 with PSM . My car also has coilovers , big sway bars and every single bush has been replaced with powerflex ones .

A limited slip diff in a 996 is a fantastic upgrade .
When you Mash it off the line it doesn't bog down like PSM cars normaly do , the car gets great traction so the PSM doesn't have to kick in.

Night and day a better car . The deceleration tractability heading hard into corners is amazing . When you come back on the throttle on the way out it just has monster grip.
Turn the PSM off and it's a drift scalpel .