Coleman

So my 993 had been in the air with the tranny on the bench for the past 7 days.. (it's at Hergesheimer, thanks to Phil's and others recommendations- Plus Mark is chummy with Jeff Gamroth (Rennsport systems, Alex Job team etc..) who had modded my old 964 tranny so I knew I was in good hands..) ______ So now since the mechanic has been in there, he found that the shift selector pin had dropped out and was laying at the bottom.. the 1st and 2nd gears look a little rough yet the 1st and 2nd synchros are within spec. on the down side, the diff is on it's last legs.. he said that it needs to be replaced, so we come to the questions..

I have ~somewhat budget, but it's not to say that I can't have some fun.. I'm adding a RS clutch and flywheel, RS tranny mount; I'd like to do some gears, but those may get too expensive real fast.. mark had mentioned GT LSD differentials or upgraded differentials-.. are these really worth it? he mentioned that Qualife was trash.. bang for buck on the GT/LSD differential Vs. stock? is stock okay?? there is 60k on this tranny, seems a bit early for a new diff? but then again, never sure of what kind of driving the PO had done.. never tracked it, but there were some differential gear chips that I had found on the magnet during a tranny oil change, so my guess is that the PO had some fun with it, or his wife used it as a coffee grinder.. I will do some track work with this car, not too extensive, maybe a few times per season.. the stock diff should be okay for this?? Thanks in advance for any wise comments..

Coleman.

DJF1

You will get a better benefit from doing a regear while you are at it. 3,4,5 is what will make a big difference to you. I personally would leave 6th alone for easy cruising on the highway. On track you never really go beyond 5th even on the fastest tracks.
As far as difs go, the stock LSD usually wears out ( mine is gone at 40K ) so depends on how long you keep the car and how hard you drive it. The ultimate solution would be a Porsche Motorsports LSD which is bulletproof but at $1500 plus install labor , not a cheap proposition. I guess what I'm trying to say since you are on the budget look to fit the regearing into it instead of an LSD. The results will be far more significant than an LSD.

kary993

I would regear 3,4,5, and 6th. But then I almost solely track my car these days so 6th gear is of little use on a track. A friend of mine did his and got the Porsche motorsports limited slip and really likes it. Not cheap but then since you are in there might as well take car of it now. Are you considering stock gears or racing gears?

Greg Fishman

Why can't you just rebuild the factory diff to save some $$?

Coleman

I'll ask if there is something left of the diff to rebuild...

Greg Fishman

If you want/need a good used one, send me a PM. My mechanic usually has a bunch around that he could set up for you.

Coleman

What are the differneces if any between the Porsche Motorsports limited slip and the GT limited slip?? Cost? Value??


Coleman.

Greg Fishman

When you say "GT" I assume you mean Guard Transmissions? If so, I wouldn't hesitate to use any of his parts. I have his gears and diff in my car and it has been very reliable. I think my transmission is on its 5th season since re-gearing. Of equal or more importance is the shop putting it all together and setting the R&P correctly among other items. I have seen my mechanic spend close to a day getting the R&P backlash perfect and it is part of the reason Porsche Motorsports send all their transmissions to him.

Terry Adams

I am leaning towards replacing mine with the Porsche Motorsports. Any advice, and an installer in the SF Bay Area?

As an alternative, anybody installed a Phantom Grip LSD ?

Greg Fishman

Terry,
Doesn't look like they have an application for the 911's. Personally I would stay away from it, if it is a "new" device.

I have also sent you a PM.

kary993

Coleman, so what did you decide to do?

Coleman

I'll speak with them today.. I thinkI may go with a GT diff, but I'll try to figure out if the cost over the Porsche Motorsports one is worth it. I may have to get a new 1st and 2nd gear as well.. (hey synchos are free when you buy the gears!!! Woo!)

Will keep you posted.

Colman.

Fred R. C4S

Coleman,

FWIW, re-gearing will make a fantastic change in your car's performance. I did this on my 993 C4S. However, I'd suggest leaving 6th gear alone. You'll appreciate the lower revs at interstate cruising speeds. If i had to do it again, I'd have left 6th stock.

Cheers,