Bill Verburg

Nominal 25% lock on acceleration 65% lock on deceleration. But that doesn't tell the whole story. The more friction faces and the more preload the greater the breakaway torque in either mode, friction material makes a big difference too just like w/ clutches and brakes. The # of friction faces depends on the # of inner and outer splined disks and their mounting sequence.

There were 2 different manufacturers of lsd, GKN and ZF and there were 3 types of GKN, one of which was used in the motorsports lsd

Paul902

Interesting, Bill. Do you know how many of the 4 types allow for use with 4 plates? Is it just the GKN type used for the motorsports LSD, or others as well?

Bill Verburg

For the years form '89 - 98, Only the 964RS, 993RS and 964t lsd used the more robust 2 inner + 2 outer plate/side arrangements.

g50/10, 52, 30, 31, 32, 33

pcar964

Would never buy a Porsche without LSD

Mark in Baltimore

Why? You can always add it later.

Bill Verburg

You would have a tough time adding the 4 channel ABS that goes w/ lsd in the M220 option package.

Terry Adams

That is why I bought a whole new Guard LSD for $2200 on the RL group buy a couple years ago. Sold my factory LSD for $400 to offset the cost. The installing shop said the factory plates were about 80% worn. (Street only, no track)

Bill Verburg

While the Guard lsd is much stornger than the oem GKN or ZF, it is also overkill for a stockish 993.

Pull the lsd rebuild w/ Guard plasma sprayed friction disks and reinstall. There is no muss or fuss w/ shims etc as long as the same case is reused. I think Martin Schact recently went that route.

Downside is the car is out of commision for however long it takes to rebuild the lsd.

Terry Adams

I rack up a lot of DD miles, and I am not a patient guy, so that was an issue. I did the swap before I saw Martin's story.

Mark in Baltimore

True, but my point is that one should not dismiss a car that does not come from the factory without LSD, especially if it's a street car. I added a limited slip to my car and it goes (and stops) just fine. On the track, I drive it a good bit harder than the average road-going 993 owner.

pcar964

Sure, for $$$$

chris walrod

Good advice, me thinks! The plasma sprayed plates will last A LOT longer than the factory originals, even if only a two plate version. They arent more than ~$65ea.

ZombiePorsche44

That may be true but if you have the standard 2 disc LSD and the car has more than 30-40k, the discs are almost always toast and need to be rebuilt by Guard at a cost of around $750.00, so no matter what LSD you get or have, it is still a lot of $$$$$

ZP44

TheOtherEric

If that's true, his prices went up drastically in the last 2 yrs. I paid $400 plus shipping in Apr 2005.

chris walrod

I have had a few done for right at $400 including two new carrier bearings.