924Board.org

[porschebadger]

Hey y'all,

I've had my 80 931 for 15 years now, and the vast majority of that time its been in storage. I am finally getting around to sorting the car out mechanically.

The car always ran ok for me, but suffered a hot start issue (wouldn't start when hot - possible bad ground?) and the snailshell gearbox has bad synchros in 1 and if I remember right 4.

I've acquired a complete 81 parts car and was wondering if there are recommended upgrades from the S2 car that I should pull off the car for my S1?

I was considering pulling the gearbox and required swap parts from the 81 to put in my 80 since I wasn't sure how easy or cheap it would be to rebuild the snailshell? Pros / Cons with this?

Any input would be greatly appreciated!
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- 1980 931 - Silver/Graphite Two Tone - Optional 5 Lug and Leather
- 2003 Maserati 4200 GT
- 1973 Jaguar XKE 2+2
- 1994 Range Rover SWB
- 1975 K5 Blazer
- 1996 Ducati 900SS SP
- 1989 964 C4 - Sold : (
- 1987 951 - Sold : (
- 1999 986 - Sold : (

[924RACR]

Agreed with the tranny swap. Did this on our '79 NA racecar; not really a big deal IMO. Just swap torque tube and trans, probably as a unit, complete with shifter, and rear suspension, easy peasy.
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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

[chuck21401]

I have a 1981 931 with 1980 engine and transmission. Previous owner installed S2 throttle body and charge tube. Not sure if that enhanced performance but made it a lot easier to add an intercooler.

The G31 transmission in my car needs at least synchros in 1st and 2nd, probably more. I'm thinking about having mine rebuilt...swapping in the later transmission, etc is an option but I don't have any of the parts.
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1981 Porsche 931 w/S1 engine & g31 transmission. Water-cooled intercooler

[porschebadger]

Thanks for the replies on the gearbox and S2 throttle body.

931's aren't exactly setting the classic car market ablaze, but my main hesitation with keeping the G31 (besides difficulty of sourcing parts for rebuilding) would be taking some of the original character away from the car.

I always found the dogleg pattern a bit annoying, but unsure if swapping it out for the later box is doing the car a disservice in some way?
_________________
- 1980 931 - Silver/Graphite Two Tone - Optional 5 Lug and Leather
- 2003 Maserati 4200 GT
- 1973 Jaguar XKE 2+2
- 1994 Range Rover SWB
- 1975 K5 Blazer
- 1996 Ducati 900SS SP
- 1989 964 C4 - Sold : (
- 1987 951 - Sold : (
- 1999 986 - Sold : (

[chuck21401]

Another consideration might be the gear ratios.

I like the dogleg shift pattern but have found that 1st gear is too short and 5 gear is a bit tall.

I came across this document looking for information on the G31...it includes info on various 924/944 transmissions including gear ratios.

https://jamesrgregory.com/Porsche/G31%20Transaxles%20-%20Pete%20Tinucci.pdf
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1981 Porsche 931 w/S1 engine & g31 transmission. Water-cooled intercooler

[Cedric]

I dislike the sloppy shifting of the audi boxes, even with upgraded linkages etc i haven't driven any audi boxed car that is even half as good as my g31 (though they are faster to shift). But it is a more daily friendly box, with more common parts. But i like both the design and feel of the G31

The ROW gear ratios are pretty spot on for road driving, they went a weird way on the us boxes though with the changes they made.
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1980 924 Turbo
www.instagram.com/garagecedric/