HODY905

Can anyone tell me where to find the transmission gear ratios for the 964 Euro cup cars?

Tom W

I have all the ratios for G50 transmissions. Do you know what was in a 964 cup car? Unlike the 6-speeds, there is not much variability in the ratios used in the 5-speed versions of the G50. My info doesn't show any "special" transmissions like the club sport G50/32 or the RS G50/31 6-speed versions.

Cupcar#12

G50/10 tranny?

1st = 3.154:1
2nd = 1.895:1
3rd = 1.407:1
4th = 1.086:1
5th = 0.868:1

Shifter Ratio = i=3.4

<Added> this is for the American Cup car but i believe they are the same for the euro cup as well

Tom W

Rob, That was my guess too. There is also a G50/50 that's a 5-speed and I wasn't sure what it was used on.

The G50/01 for reference is
1st = 3.500:1
2nd = 2.059:1
3rd = 1.409:1
4th = 1.125:1
5th = 0.892:1

Cupcar#12

<edited>
Updated - G50/50 is the 930 Turbo 5 Speed. still trying to figure out if this was the tranny in the 964 turbo 3.3L

I was wrong here ->(RSR & Turbo LeMans I believe)
(i'm rusty right now so not 100%)

Cupcar#12

posted update to previous post re: G50/50 - 930 turbo 5 speed box

Cupcar#12

whalla
G50/00 = 911 Carrera, R.o.W.
G50/01 = 911 Carrera, USA/CND/J/AUS
G50/02 = 911 Switzerland (very short gear ratios)
G50/50 = 911 Turbo world wide, 1989 only
G50/52 = later Porsche turbo boxes ZF ltd. slip

Gear
Transaxle 1 2 3 4 5 Notes
G50/00 3.5 2.059 1.409 1.074 0.861 (after 1988 0.868) Final drive ratio 9:31
G50/01 3.5 2.059 1.409 1.125 0.889 (after 1988 0.892)
G50/02 3.154 1.895 1.333 1.036 0.861 (after 1988 0.868)
G50/03 3.5 2.059 1.407 1.086 0.868
G50/04 3.154 1.895 1.333 1.029 0.868
G50/05 3.5 2.059 1.407 1.086 0.868 Final drive ratio: 3.333:1
G50/10 3.154 1.895 1.407 1.086 0.868
G50/50 3.154 1.789 1.269 0.967 0.756 Beefier internals, differential cover, and case
G50/52 3.154 1.789 1.269 0.967 0.756 Not as strong as G50/50

Tom W

I have an Excel spreadsheet with all the ratios for the various G50 boxes (both 5 and 6-speed) and rpm to mph conversion if anyone wants a copy (just send me an email). I created it when I had my 993 transmission re-geared to short ratios.

ltc

My 92 Service Information Technik WKD 497 620 (nice booklet) agrees with Rob's G50/10 numbers.
FWIW, the reverse gear is 2.857:1

On page 3-3, the description of the transmission is as follows:
Five speed manual transmission G50/10 (worldwide).

All 911 Carrera RS models are fitted with transmission G50/10, which has a number of modifications compared with the transmission in the current 911 Carrera 2.

*Harder central rubber bearing in the front transmission cover (60 Shore)
*Special ratios for first and second gear.
*Limited slip differential as standard: (locking effect: decel up to 100%, acceleration up to 20%)
*Steel synchronizing rings for gears one to four
*Modifiied shift sleeves (bevel angle)...listed as 120deg on page 3-5

Cupcar#12

i believe that is correct as well (RS = Cup G50/10) - The US Cup is definitely the ratios listed above for the G50/10 & uses the same tanny as the Euro cups but...since i don't have it from Porsche I cannot be 100%

I'll try to post the service technik for the 92' RS this weekend to the cup site, i also have the setup sheet and instructions to post as well

Adrian

The G50/10 gearbox was developed for the 964 RS for the NGT class and for the new 964RSR for use under FIA and ACO rules.
To claim it was fitted to the Carrera Cup series 964s is a poke in the dark.
It may have been after it became available, but all the posts here provide no evidence it was.
The first 964 Carrera Cup was built for the 1990 season (developed in 1998) and the G50/10 did not exist at this time.
The Andial Cups in the USA were based on the Carrera RS not the Carrera Cup.
In 1990 the only LSD available for the 964 G50 series gearbox was the 40% lock version.
The 20/100% was developed for the 1991 964 Turbo and the G50/52 gearbox.
The Carrera RS NGTs for racing teams were delivered with the 40% lock LSD. The road versions were fitted with 20/100% LSD as standard, the 40% available as an option.
The best source of what gearbox used for what Carrera Cup series, (1990, 1991, 1992, 1993, 1994) and the multiple range of ratio combinations they used would be Porsche Motorsports Germany.
You could also try to contact one of the teams that used to run these Carrera Cup cars such as Roock or Konrad.
A 964 Carrera Cup is NOT a 964 Carrera RS. The Cup car existed long before the RS.
Based on the information I have uncovered since I wrote my 964 book I am 100% sure the gear ratios used in the G50/10 were not used in the Carrera Cup cars because the Cup cars were gear ratio limited to a top speed of 210kph for seasons 1990 and 1991 with their 265hp engines.
I am not sure what speed they were gear limited to from 1992 with their 275hp engines.
They only weighed 1120kg.
There were no rules for Carrera Cups used in the Porsche Cup or Super Cup series. If the Carrera Cup was used in another series such as Le Mans then they were radically modified to comply with the series rules.
Finding a genuine original Porsche Carrera Cup is very difficult because of these conversions.
A similar story applies to the 993 Carrera Cup which was launched in November 1994 for the 1995 Porsche Cup series.
Ciao,
Adrian.

Cupcar#12

so i guess at this point we need verification from Porsche motorsports before we can find out - that's fair.
let me see what i can do.

Adrian

Unfortunately my last contact/source from within who was there, who could find this information, recently retired. His last job for me was the GT-1 story where he was able to supply all the chassis numbers, proper tech specs etc.
My current source for Porsche Carrera Cup information is Peter Schneider who wrote a book on the Porsche racing cars from 1948 to 2003.
One other piece of information that I have been able to discover is that the original purpose of the 964 Carrera 4 RS (20 built) was to compete alongside with Carrera 2 Cup cars. They were built to the 1990 Carrera Cup specs. The idea did not seem to take off.
Mind you I do not think anybody has actually researched the various Porsche Carrera Cup series down to the actual participants.
Didn't somebody on this forum post some time back that they had the "964 Carrera Cup" parts catalogue? Surely this would contain some relevant information. At least part numbers for the gearboxes used in the different racing seasons and maybe various gear ratio sets.
Anyway good luck. I am too busy to spend much time on this but I will also keep my ear to the ground and see if I can find some verifiable documentation.
Ciao,
Adrian.

Bill Gregory

The 1992 Carrera Cup parts listing only shows a handful of transmission parts, which are the transmission mount (hardest rubber, still available), 1st gear, 2nd gear, and the 40% locking differential.

Cupcar#12

i have 3 rev's of the 964 Cup parts lists - none mention the replacement box number. and no other tranny parts other than what bill mentioned above.