Lord_Galva

Anyone here successfully swapped out the standard diff for a Quaife or factory LSD?
I've heard from many 220 owners that it is the single best option from the factory for autocross/ track-days.

badcoupe

I would love to do it to mine, I did it to my 951 long ago and it's much better.

Cloud9...68

The previous owner of my car installed a Guard torque biasing differential (I have to confess I have no idea how it works, much less how it is different from other types of limited slip diff's, which I also have a very limited understanding of), so I know it is possible. I've never driven a 968 with a stock, open diff, so I can't comment on the impact of a limited slip diff. Many have said it makes a huge difference, so I would go by these inputs. Personally, I've never been in a condition where I've been wanting for traction, and I've tracked the car extensively, so I'm a little skeptical that a limited slip diff would make that big of a difference on these modestly powered cars, but again, a lot of people say it does. Kind of an expensive upgrade, though, so it might be a good idea to see if you can drive one with one installed to see if you can tell a difference before plunking down the cash.

blue44

it's one of the best upgrades for a car that's going to the track or an autocross. combine with M030 sway bars and a set of wheel spacers and it makes a huge difference...

Donn

odurandina

yes,

i've done it with the latter LSD. installation was completed by Kevin Gross.

not yet driving it though.

mikew968

My street car with open diff progressed into a track car. During that transition I had a Guard lsd installed. The problem on the track is as you apply power thru the corner the inside wheel begins to spin. Not at first but as you get faster the spinning gets worse. I have a M030 car street 968 w/o 220 and I notice it most on slow speed tight corners and in the rain. The street car can get to 80% of performance pretty easy w/o an LSD so it is not critical on the street. On the track though is a different story.

car_slave

How hard of a job is it? Can it all be done from the diff side panel or do you need to go deeper than that?

JDS968

I have an M030 968 with a Quaife (functions like Torsen/Guard/Peloquin). It's enormously useful. Without it, the car is easily capable of spinning the inside rear on tight corners, especially ones like the Safety Pin at Sebring.

On the street, it's nice in the rain.

I didn't install it myself, but I can't imagine there's any way in the world to do it without removing the transaxle.

odurandina

no, you can not get there from that end of the box.

the entire transmission must be dis-assembled then the LSD installed and so on......

followed by the customary phone call from Roger, Scott or Kevin informing you that they can't in good conscience, re-assemble the box and deliver it to you without replacing a good number of expensive critical parts..... an LSD install is another since we're already down there situation.

8~10 shop hours [nominal].

Krag50

A LSD can be installed without removing the trans-axle from the car. I've done it twice and It's relatively simple. Drain the oil, drop the axles, remove the axle flange stubs, pull the whole LSD unit via the side plate. The trick is getting the new unit set-up right with the correct measurments via shimming. But this can be done by using a CMM machine and some simple math.

Cloud9...68

Interesting thread. As I said, I've tracked my car fairly extensively, but I'm by no means a track veteran, and I'm a long way from racing competitively. But the vast majority of my driving has been on tight, technical tracks, where I got my lap times down to among the fastest guys out there (at least among the beginner/intermediate drivers), and I've never come close to spinning my inner tires, with my Guard diff. Maybe when I'm done with the project, which includes a completely rebuilt engine, 18 lb flywheel, ~250 lbs taken out of the car, radically modified suspension, etc.

Lord_Galva

Good points to think about.
I'm getting noise from the tranny while shifting and turning.
Have a bad feeling the diff is screwed.
Shifting = loud clunk
Turning = grinding
I'm taking the car to the shop who did the p/b work.
And I'm not driving it. Way to scary.

car_slave

Thanks Krag - I wasn't really concerned about dropping the gearbox. Just wondered how deep you had to go into it. I've rebuilt a diff unit before on my Range Rover P38 and know quite a bit about reading gear engagement patterns.

grants_968

Did so on my HMR 968 Porsche. ... more in the two articles on my 968 that I wrote for 9 Magazine.

sydneyman

what year p38? i have an '02 and im thinking of having the front end rebuilt soon. first i need a new motor as mine cooked after losing the radiator...

great choice in vehicles btw!
Chris