Manny Alban

Hi everyone. I'm sure this has been discussed, but I couldn't find anything on a search. Does anyone know of any ring and pinion options that were available on the 1990-1994 964 C2's? I know there are Porsche Motorsport R&P's, but I was wondering if you could check off an option box when you bought a new C2 back in the 90's. Thanks!

Geoffrey

Manny, there were not R&P options you could check. The G50/03 has a 3.44 R&P and a G50/05 has a 3.33R&P. So, basically the 92 and later models have a taller R&P. For club racing, I'd rather have a G50/03.

george_k

Manny, take a look at page 137 in the 964 parts catalog, it shows both ring and pinion ratios as Geoffrey mentioned and part numbers, also look at the MSP pages which show all of the options that were available.
http://www.boardwalkag.com/catalog/C...SA_KATALOG.PDF

Jeff Curtis

Yeah, those ratios wind out to be the popular 9:31 R&P (very common in most C2/C4s) and the 9:30 which from what I have found winds up in later RS Americas only?? ...I may be wrong on that one.

The only "short" option for a G50 R&P, according to Paul Guard and some other sources I've talked to is the 8:32 "Motorsport" R&P which tends to shorten the lower gears in a "regular" G50 gearbox a bit much.

The ideal gearbox, no doubt, would be to get the longer 1st/2nd "Cup" gearshaft and have the 8:32 ratio from 3rd gear on up like the Cupcars, at least most of 'em I've seen.

OR, take your original 9:31 or 9:30 R&P and get a shorter 3rd/4th/5th gear...which would be the more "economical" option, considering the 1st/2nd gearshaft option is well over $3k once the fat lady sings.

Either way, Porsche gearboxes are just plain pricey to upgrade/maintain/rebuild.

Manny Alban

Thanks guys. Have patience with me since I'm not very technical. This posting is for a friend of mine. I've got the Motorsports R&P. Love it. No good for Daytona, but perfect for VIR where I go into the red right at the braking zone on the back straight.

dholling13

Geoffrey,

What ring and pinion does the 964 turbo g50/52 have?

Geoffrey

3.444

TIM COSTA

Hey Guys,
Im being told by my machanic that the 3.44 R&P was only available in the tiptronic????

Tim

Geoffrey

Your mechanic is incorrect. The only 5spd 964 trans to have a 3.333 R&P is the G50/05, all fo the others, G50/03, 04, 10, have 3.444. The tiptronic C2 transmissions have either a 3.667 (A50/02) or a 3.555 (A50/03). Tell your mechanic to look it up in his technical specifications section of his service manuals. If he does not have the service manuals, find a new mechanic.

Jeff Curtis

Tim Costa, a 3.44 ratio (9:31) R&P came in a regular C2 and some RSAs...I believe the RS and later RSAs came with a 3.33 ratio (9:30) R&P...I may not be accurate with the ratio regarding RSAs.

Cupcars came with a 4.00 ratio (8:32) R&P and the smaller 1st/2nd gearshaft which essentially made 1st/2nd gear similar to that of a 9:31 R&P gearbox.

Geoffrey

NO, NO, NO, RSAs came only with a G50/05 transmission which has a 3.333 R&P ratio. I believe this was also a running change to the C2 in 1992 as well. The 964 Cup cars have a G50/10 gearbox which has a 3.444 R&P ratio. I have never seen a 964 Cup in factory specification with a 4.0 R&P.

Jeff Curtis

You've never seen a 964 Cup with an 8:32 (4.0) R&P?? A friend of mine had one of the Andial Cupcars and it supposedly had an 8:32 with the longer 1st/2nd gears/shaft so his 2nd to 3rd gear change was like hitting nitrous!

Yeah, now I remember the change to a 9:30 (3.33) R&P in 1992, I saw that somewhere but don't recall and being that you say ALL RSAs come with the 3.33, and they were made 1992 on...that makes sense.

Geoffrey

The USA Cups came with the 3.444 R&P because they also have a G50/10 transmission. If the car you drove had a 4.0 R&P it was changed out by someone other than the factory. First and Second gear in the G50/10 are different than the G50/05 and /03, using the G50/04 first and second. These differences are minor.

I have seen C2 gearboxes with a 4.0 R&P, however, someone replaced the factory R&P with the motorsports 4.0 R&P. This conversion is quite common.

TIM COSTA

Thanks Guys, I had another shop owner fax me a copy of the PET pages that refer to the information discussed in this thread. Its all very interesting but there still seems to be some confussion about how much someone could possibly gain by such a small change in ratios. That is with out changing anything else.

Mark in Baltimore