G50/50 convert question

[vinyl_tien]

HI
I want to convert my 86 930 to G50/50 trans, plan to cut the torsion bar also reinforce it.
My question is can I use original transmission mount or do I have to buy a mod one like turbokraft made?
The second question, With this setup, Do I have to move my engine mount backward? to make more space for G50?
Need you guys input, thanks!

[Rodsrsr]

I dont think cutting the torsion tube is the preferred method anymore. Short Bell housing G50 or having yours shortened is the way to go.

[totle]

As rodsrsr state, not the best option to cut the torsion bar.
If cutting the torsion tube, it will have to be modified and stiffened. Also the shock towers will have to be stiffened to be able to take the load from the coilovers.

I have just recently upgraded my 79 930 with a g50/01 transmission.

I shortened my g50. I took time to research since I did most of the job myself.
I has a machine shop to shorten the bellhousing and axel for me.

There is quite a list of other parts that needs to be upgraded but I guess you are aware of all the parts needed.

I used the original transmission mount, but had to weld on an extra flange since I had to move it backward.

[vinyl_tien]

Thanks Rodsrsr and totle
I live in Taiwan, it is hard to find machine shop to do shortened G50.
Right now my car is in body should, I already have reinforce parts for shock tower and coil over kit for rear suspension.
I have 930 shorten bell house transmission(from a 76). It will go into my 73 911 next year. I also have a 87 930 transmission which pull out from my car.
Should I take it as a sample for shortened G50? or just compare the different?

[TurboKraft]

Is there a reason you want the 1989 G50/50 Turbo instead of a 1987-89 Carrera G50? Everything else equal, yes, the G50/50 has a larger ring gear and thus a higher torque capacity -- but it is also a longer transmission (outside dimensions) with tall gear ratios for top speed.

Frankly, the Carrera G50 ratios are really more fun for street driving, and if you need more top speed then you install a Turbo 5th gear. And I've put 700hp/600tq through a shortened Carrera G50 in a car using 12" wide near-slick tires, no problems.

Shortening the transmission housing makes it far easier to install, almost a bolt-in to a chassis that had a 1978-88 "long" 4-speed transmission.

[vinyl_tien]

Hi Turbokraft
Thanks for the tips, really appreciate, the reason I want to cut TB is my car is in bodyshop, I had do some research and tell my bodyshop techman, they tell me they can do it cheap in Taiwan(extra 1000usd).
I don't know cut the TB and reinforce will strong enough like factory.
If I want to shorten my trans, I can ask my tech to separate bell house and main shaft and ship it to you, is that possible to done it?

[TurboKraft]

Sure, you can ship us a mainshaft and bell housing and we can shorten them for you, ship them back ready to install.

Cutting out the center of the torsion bar housing -- this is okay, provided the body shop takes care:
(a) to not let the torsion bar housing move relative to the chassis, and
(b) reinforce it to the chassis a lot.
After all, it is the inner trailing arm mount, too. It has to be strong and in the correct location.

Not long ago we had a car in where the center had been cut out, and they had allowed the cut ends to shift relative to the chassis prior to re-welding. Proper alignment was impossible, and it had to be re-done -- triple the work vs. doing it right the first time.

Cut out the tunnel enough and you can fit a 993's 6-speed if you want.

[Tippy]

Chris, the 700hp car had a billet diff cover I assume?

[Anastasios]

I will not cut the torsion tube at all.
You can have your bellhousing and mainshaft shortened as already mentioned.
Also how many HP do you expect from your engine ?
G50/50 is double or even more pricey than an non turbo G50...
Many people use with good results an non turbo G50 with a turbo engine...

Tasos

[TurboKraft]

Originally Posted by Tippy

Chris, the 700hp car had a billet diff cover I assume?

No, that particular one had a 993 side cover fitted to it.
At the time, the billet side covers were solid slabs of aluminum, not very high quality. They're better now, and I'd incorporate one in a transmission used with a very high torque engine.

[Hams930T]

Originally Posted by TurboKraft

No, that particular one had a 993 side cover fitted to it.
At the time, the billet side covers were solid slabs of aluminum, not very high quality. They're better now, and I'd incorporate one in a transmission used with a very high torque engine.

Do you guys offer a G50 conversion package? I would really like to discuss with you if you guys do....

Thanks,

Chris.

[TurboKraft]

Originally Posted by Hams930T

Do you guys offer a G50 conversion package? I would really like to discuss with you if you guys do....
Thanks,
Chris.

Yes, contact us by phone, email, or PM and we'll go over the options and details for your build.

[Tippy]

Quote de Tippy

Chris, the 700hp car had a billet diff cover I assume?

No, that particular one had a 993 side cover fitted to it.

At the time, the billet side covers were solid slabs of aluminum, not very high quality. They're better now, and I'd incorporate one in a transmission used with a very high torque engine.

Thank you so much! Going to order one soon and put my worries to rest.

[Rodsrsr]

Originally Posted by Tippy

Thank you so much! Going to order one soon and put my worries to rest.

Its my next project as well.

[mamut]

Originally Posted by vinyl_tien

Thanks Rodsrsr and totle
I live in Taiwan, it is hard to find machine shop to do shortened G50.
Right now my car is in body should, I already have reinforce parts for shock tower and coil over kit for rear suspension.
I have 930 shorten bell house transmission(from a 76). It will go into my 73 911 next year. I also have a 87 930 transmission which pull out from my car.
Should I take it as a sample for shortened G50? or just compare the different?

You should get in contact with Albert, at Blank, he is in Taiwan, (Going Superfast) he can provide you with the services you need done on your tranny.

[Tippy]

Quote de Tippy

Thank you so much! Going to order one soon and put my worries to rest.

Its my next project as well.

You know, now I can't find one....

[mamut]

Originally Posted by TurboKraft

No, that particular one had a 993 side cover fitted to it.
At the time, the billet side covers were solid slabs of aluminum, not very high quality. They're better now, and I'd incorporate one in a transmission used with a very high torque engine.

What do you mean by the late covers been better, as in looks? 'cause I will think that a slab of aluminum will be stronger than a ribbed one, just my opinion thou.,
Stefan.

[TurboKraft]

Originally Posted by mamut

What do you mean by the late covers been better, as in looks? 'cause I will think that a slab of aluminum will be stronger than a ribbed one, just my opinion thou.,
Stefan.

Actually, a solid slab is not stronger in this instance, nor is it weaker. Most of the metal is seeing no real load, so it's just a lot heavier.
If correctly lightened, there is no loss in stiffness and support for the bearing. This is easily confirmed with load simulation applications integrated into 3D modelling software like SolidWorks.

Example: WEVO's super nice billet side covers for the 915 transaxles. A fraction of the weight of a solid slab, no loss in rigidity.

[TurboKraft]

Originally Posted by Tippy

You know, now I can't find one....

Billet side cover, or a G50 transmission?
Last week and earlier this week I came across a few G50s. Email or PM me.

[Tippy]

Originally Posted by TurboKraft

Billet side cover, or a G50 transmission?
Last week and earlier this week I came across a few G50s. Email or PM me.

No, the OEM 993 side cover. I'll machine the speedo boss.