I’m running a 3.2 chassis with a 964 3.6 engine mated up to a 915 gearbox. The gearbox has done around 120-130k miles without rebuild so with the age, mileage and the additional loads placed upon it from the 3.6 conversion I did around 10k miles ago, needless to say it is becoming pretty stretched, crunching more and more and generally worn. It has always had a factory short shift which possibly exaggerates this and more recently a Seine gate shifter. Ideally I would have dealt with it when I did the 3.6 conversion but time and money constraints did not allow.
Now I’m not going to get drawn into any debates over 915 v G50 because it has all been discussed far too many times before. What I would say is that I have owned both and personally feel that the G50, albeit slightly heavier with more complications such as hydraulic operation does allow for a bit more clumsiness, faster shifts and is arguably a slightly more robust unit. I am trying to compile a rough argument against rebuilding my 915 verses swapping it for a G50 unit from the ’87-’89 Carrera.
Trawling through many old threads, the thread that stands out the most for good information is this:
Fitting 6 speed G50 to '89 Carrera
And the thread with the most amount of promise but eventually fizzled out was this:
(Really wish you’d carried on with that one Blackbyrd!)
915 to G50 Conversion on my Euro 3.2 911 SC
This for sale details some of the parts with photos that need to be modded:
FS: G50 Shortened Bell Housing/Main Shaft/Fork
All I want to do is try to seek some answers from people who have either done the conversion or have knowledge of it without cluttering up anyone else’s thread so that I can decide whether to start hunting for a G50-00.
I would like to retain the torsion bar set up instead of going to coilovers and would really like to not have to cut into the torsion tube. So basically a nut and bolt conversion (apart from the shortening to the ‘box). I have read that some do have to and some don’t which always puzzles me as I thought it would be a bit more of a black or white answer!
As far as a parts list goes, I’ve figured it will need:
G50-00 Gearbox (Not sure if this is the only G50 Variant that fits but appears to be the shortest)
G50 Pedals and master cylinder (possible aftermarket – Tilton?)
3 x Hydraulic lines
G50 Shifter assembly
G50 front mount / adaptor to 915 chassis (Patrick Motorsport?)
Reservoir and line
Slave Cylinder
G50 starter motor
Clutch kit
Flywheel (Patrick Motorsport?)
And the work involved other than fitting the above is:
Shortening the bellhousing of the G50 by the 29mm or so – Are there any threads or info out there on the best way to do this?
Shortening the main shaft of the G50 by the same amount - Are there any threads or info out there on the best way to do this?
Do you have to completely dismantle the G50 to remove the main shaft to shorten it? I've seen people quote $1000 for the work which seems a lot for simply doing the machining work so presumably the rest is in the labout to strip and reassemble the 'box?
Any advice on offer or anything that I have missed out there would be great as even if I don’t do it and live with/rebuild my crunchy 915 - It may be useful to others
