Transaxle

Is there anyone running a G31 (924 turbo transaxle) in a 951 ? I would like to use such a trans cause it seems easier to get different gear ratios for this 911-style unit...

Is there anything to look for ?

tone3721

So, this thread is pretty old. 6 years later is anyone around here doing/done this? Ive been looking into the g31 more. Considering a custom TA for my 3.0L, would be nice to have something sick sitting on the side when I most likely, inevitably break something. Would be nice to know for sure my TA will hold up to whatever I throw at it. Seems like Porsche might have had it right with the G31/03. The GTP was pushing simlar #'s to what I will be, seems to make sense.

Van

Good question. I look forward to finding the answer.

pjburges

From a design standpoint, I like the G31 unit, it has beefier bearings, shorter internal shafts, more gear surface area at less steeply cut angles... everything that would indicate a stronger unit than the Audi design. Thats not to say the Audi design is bad though.

The differential ring gear is also a good bit beefier on the G31 unit.

333pg333

There is a bit of info in here about this also with references to other forums. Do a search and see what you come up with. There seemed to be an overall feeling that while the gearing offered some choices and construction of some of the components were strong, the casing itself might be called into question. This is a bit of a favorite with the V8 conversion crowd.

gt37vgt

Pat as your agent i feel we could better capitize on your sponership deal if the glare was fixed from the Avator photo

Raceboy

G31 is a strong box (confirmed up to 450hp on heavily modified Swedish 931 and another one running 374 hp, also from Sweden) but it has very weak 1st and 2nd gear syncros. One possible solution (allegedly, because I have no first hand experience) is to machine 930 syncros and dog teeth to G31.

gt37vgt

mmmmmm dog ...... so how big a deal is it to convert something to dog ?

333pg333

What is the big advantage of dog engagement? What is it in reality? Just straight cut gears?

Raceboy

You misunderstood me.

"Dog-leg" means gear pattern, i.e. 1st gear is to down left. Dog-teeth are part of the syncro mechanism, not straight-cut teeth like on race gearboxes.

A.Wayne

The 931 trans will require the 931 t/q tube .............................................

The trans use 915 gears , from experience stick with the 951 trans . The big HP
cars went with Hewlands when they moved away from the 951 trans.

If you are building a track car the stock trans with a pump and cooler will suffice
for most ..

tone3721

Its a almost 100% street car. Im just looking for peace of mind, that I can drive how I want when I want. I dont abuse my cars, but still.... Im thinking I could throw 10k(obviously the less the better) at a TA project over the next year. There has got to be a solution that Porsche has already dne for high tq setups. Not sure where to begin tho. Im in the process of researching, and trying to even figure out what all my options are. Still digesting alot of info. Id like to keep things as close to the 944 pedigree as possible. No major outcrosses! The G31 seems to be pretty close to fitting my needs. Not real expensive either. In my spare time Im planning on researching this to the tilt. Ill post back findings, data, etc. My goal is to try and do this purely Porsche.
Ive been looking into things like the GTP as examples, sources giving me info on the GTP are conflicting with each other as far as specs go. Anybody know where to look for definitive data on the GTP? Schematics would be nice. I have only found half *** sources so far. I realize the stock TA should "suffice", but im not really one for shoulds, and maybes. There has got to be a way to fit a bulletproof TA into my car for +/-10k, and keep it porsche/audi.

Rich Sandor

Shift smoothly at all times, don't power shift needlessly, match revs, and don't force it into gear, and the stock 951 box will be fine.

I'm not saying that the 951 box is invincible, but instructing at autoX with a LOT of people over the years, I can imagine a lot of failed gears or gearboxes due to DRIVER ERROR.

tone3721

Should be fine, but not bulletproof. Bulletproof would be nice.

MPD47

Or abuse. The 931 snail is more trouble than it's worth. I considered 928 and 931 gearboxes. Decided to stick with a 968 unit.

If you want bulletproof you chose the wrong car to mod.