G50 Info

[builder]

Hi All,

I am interested in building a car that uses the Porsche Transaxle - an Ultima GTR. There are a few G50 boxes that will work:

/03 (964 C2?), /21 (993 6-spd?), /30 (cup car?), /50 (early turbo?), and /52 (964 turbo?).

What I am looking for is a crankshaft to output shaft exploded view of the components that make up the drive train. Being in the USA, I am very familiar with standard Chevy transmissions, but this transaxle-thing is new to me.

Is there a shop manual, or CD that I can get?

Thanks,
-- Scott
Reno, NV

[domster]

Look at Stig's site: www.ultima-gtr.info .... he has a page on gearboxes.

Arguably the best for an Ultima is a G50/52; these came from a 965 Turbo 2 if I remember, with longer gear ratios and an LSD. However, virtually any G50 will do, and most can be retrofitted with different ratios and LSD.

Email the Ultima factory if you need more guidance (Ted and Richard are helpful and have answered similar queries many times, and they also sell reconditioned G50 boxes at reasonable cost), or try the Ultima forum.

HTH
Domster

[nel]

A friend with an Ultima was at a recent factory open day - as I recall he said that the new G50 boxes being used for Ultima's are actually from the 996 model.

builder - if it is of help to you I can send you gearbox/diff section of the 993 workshop manual in .PDF format - this is full of diagrams of the gearbox assembly and has loads of data on the ratios aswell. Send me your email address through my PH profile if you're interested.

Niels

[domster]

nel said:

A friend with an Ultima was at a recent factory open day - as I recall he said that the new G50 boxes being used for Ultima's are actually from the 996 model.

No, these are the getrag 996 cable change boxes, which are an option. You can still buy reconditioned G50 boxes from Ultima (a completely different design, but some prefer them).

nel said:

builder - if it is of help to you I can send you gearbox/diff section of the 993 workshop manual in .PDF format - this is full of diagrams of the gearbox assembly and has loads of data on the ratios aswell.

The 993 G50 box is slightly different, being a 6 speed. They do fit in Ultimas, but check with the factory. Most builders opt for earlier 5 speed G50 boxes.

[builder]

Doomster and Nel,

Thanks for the feedback! Yes, my question isn't so much about what box to use. I will probably buy a 50/52 from the factory when the time comes. Rather, what are the parts (with a typical transaxle setup) between the crankshaft and output shaft.

What I mean is...

On a Chevy, the trans is attached through a clutch (for manual shift) or torque converter (for automatics) to the crank. The starter is connected to a geared "flex plate", which is on the crank-side. Then, there's the transmission. Out the back, there's a driveshaft connected to the differential, which may be LSD-type (Positraction)...then, two "half axles" to the wheels (spindles and rotors).

I presume there are some similarities, but I know the components are considerably different in shape and engineering. I know there are bits that go in there that I know nothing about. For example, the clutch is bowl-shaped? What's up with that? Different sized solenoides? Etc...

As you can tell, I have a lot to learn about a T/A setup. So, any exploded diagrams you have would be awesome and go a long ways to clearing up my "twisted" view of how it all fits together. Please email ([e-mail]) anything you think would help!

Thanks again,

-- Scott