cobalt

Does anyone know what LSD was used for option 220 for these cars?

I did a search and I got all sorts of info, none of which is consistent.

What I have read was that the cars were offered with one of 2 available LSD's of the time. Either 40% which I am assuming is on accel and decel and the other which I have in my turbo which is the 20-100%.

I was under the impression the 40% was used on the RSA but what I have read is either unit could be installed on a C2. Other threads said that after 92 all were 20-100's and prior all were 40%. I also read that it was buyers discretion.

I don't think the one in my car is a 20-100 because it is too quiet. The turbos and I mean all the turbos with the G50/52's grind and make all sorts of noise at low speeds and even adding special additives they still make noise. I am assuming since this is much quieter it is the 40% unit.

Is there a way of telling without taking apart the tranny?

Geoffrey

The G50/03 and G50/05 have a 40/40 locking diff. The G50/52 and the G50/10 both have a 20/100 locking diff. The difference between the two is simply the ramp rate on the locking ring.

cobalt

Now the next stupid question, Which tranny came in the 93 C2?

I am assuming the G50/10 is what came in the cup or RS's.

Geoffrey

G50/03 = US C2
G50/05 = RSA
G50/10 = Euro RS, Euro Cup car, and I assume but don't know for sure, USA Cup

cobalt

Thanks Geoffrey, your a wealth of info.

JasonAndreas

Only for MY90-91 did the C2 have the 40/40, from MY92+ they came with the 20/100.


Porsche originally used a material called Gylon (teflon) on the inner discs but switched to a woven graphite by Valeo. I'm thinking that might have something to do with the noise?

Geoffrey

Jason, I'm not showing in the technical spec book that a 20/100 was offered in a G50/03 gearbox and the 92s that I work with have all had 40/40 LSDs. There may be conflicting information due to the G50/10 geabox, but my experinece and relatively small sample size has shown consistently a 40/40 on the G40/03s.

JasonAndreas

The G50.03 was only from MY90-91 and became the G50.05 in MY92 so that matches the explanation I posted but if


The spec book that I own has a bunch of errors (especially in the gearbox section) and Adrian's book is pretty clear about the G50-05.2 having a 20/100 but actually taking one apart trumps both. I've taken mine out to test but not apart to check so I can't add much.

Geoffrey

Yep, there very may well have been both installed. I prefer the 40/40 over the 20/100 btw.

ThomasC2

I have just installed a LSD togehter with a new clutch and RS-flywheel. I bought the 996 Cup LSD and the 996 Cup clutch disc and preassure plate. The clutch disc is scintered (correct spelling?!)
The 996 Cup parts are actually cheaper than the 964 LSD's. I just got a 15 min drive before the snow came but it all felt great!

cobalt

It might be me but for some reason there is more confusion about what the factory did for the 964 models than most other Porsche's.

I was hoping for the 40/40 myself for the C2 as where the 20/100 seams to be perfect for the turbo and over kill for the C2. Based on how the car feels it doesn't seam to respond the same as the 20/100 in the turbo does but that might have something to do with the extra 200hp and not much seat time in the C2.

I don't plan on opening the tranny to find out, although either is better than nothing.

It might be although even the 91-92 turbos I have been in make the same crunching noise as my 94 and since this is a 93 the only way this would make a difference would be is if they used the graghite on the turbos and the teflon on the N/A cars. Then again the G50/52 uses hardened steal in place of brass so the brass might be absorbing sound also.

Either way thanks.

If anyone else has opened there tranny's and could verify what LSD and MY, that would be great info.

David K.

I had my RSA's LSD rebuilt by Peter Dawe last year; he used Porsche motorsports parts and changed the locking to 50/50. This really made a big difference on track. I can get on the power harder coming off the corner then with the dead 40/40, also it did not cause any understeer.

Bill Verburg

the only 964s that used the 20/100 were the euro RS, Cup and turbos.
G50.10 and G50.52 trans

Oddjob

For what its worth, according to PET:

G50.03/04/05 used the 40/40% LSD (950 332 053 00) for all years

G50.10/52 used the 20/100% LSD (950 332 053 01) up through '91

'92 at later G50.10/52 used the 20/100% (950 332 053 02) LSD


Now, the 40% 950 332 053 00 is n/a, and it superceeds to a 053 06 part#. And the 20/100% 053 01 superceeds to the 053 02 unit.

Geoffrey

I find it hard to believe that anyone can tell the difference between a 40/40 and 50/50 locking diff and think it probably was the difference between a worn LSD and a new tight LSD. I wonder where Peter got the 50/50 locking rings since the motorsport parts are 40/64 and the Guard are 50/80 or 80/80.

I don't like the 20/100 because it doesn't really lock up enough under acceleration and you can feel one tire spinning from time-to-time and the 100 lockup under deceleration causes the car to understeer, especially on the track. Porsche recognized this issue and went to the 40/65 lockup on the 993 race cars. The 20% on the turbo isn't so bad since the of gas / on gas transition isn't as harsh because the turbo isn't under boost due to lag, but I'd still want a 40/40 or 40/65.