930 trailing arm on -70 tub.
 

How much work is involved to fit 930 trailing arms to an early tub?

I know I need to change the inner mount on the torsion tube, but is that it?
Is it difficult to change the mount?

It is probably best (necessary?) to replace the torsion bar tube with the 930 version. Not only are the mounts different but your tube is not connected to the rear of the tunnel in the center of the tube as is the 930 tube.

What is the (rust) condition of the chassis?

One important thing to consider is the availability of all the 930 parts necessary for this conversion. I understand many pieces are NLA or VERY expensive.

Best,
Grady

I have the opportunity to buy a -70T tub with all turbo parts (engine, gearbox, calipers, trailing arms etc) on the side. For a very reasonable price.

The reason to change the trailing arms is that Porsche Sweden might demand that to write a certificate that I can send to the "DMV" so I can register the car with this engine.

I have no idea about the rust condition, the seller says its relatively clean.
So, not only do I need to change the mount I also need to support the torsion tube to the firewall...

Does someone sell the 930 mounts, I have a distinct feeling that I have seen that in some catalog somewhere?

This is from an RSR, which has similar geometry to the 930.

http://forums.pelicanparts.com/uploa...1284054851.jpg
http://forums.pelicanparts.com/uploa...1284054869.jpg
http://forums.pelicanparts.com/uploa...1284054890.jpg
http://forums.pelicanparts.com/uploa...1284054908.jpg
http://forums.pelicanparts.com/uploa...1284054929.jpg

This last one is 930
http://forums.pelicanparts.com/uploa...1284054937.jpg

Smart Racing Products - Home of SmartStrings, SmartCamber, and other quality performance auto parts

i didn't see them listed on pelican, but you might want to ask.

rear control arm pivot boxes.

you know that the 930 arms give you wider track width. won't work on narrow cars.

Might be able to swap the stub axle to lessen the track?

I have a 930/Turbo Look torsion tube for sale. Would allow either a 930 or 915 gearbox.

Don't forget, that a '70 tub was designed for the 901/911 gearbox and if you want to put in a 930/915 gearbox, your gonna have to mod the transmission hump.

That's the one I had seen.

Wider track wouldn't be problem on this tub, its flared to accommodate 385 (!!!) tires...

I have to thinks this over carefully, it's a lot of work...

Thanks for the pictures!

Found a 76 turbo that I could take some pictures of.
The first picture shows the torsion tube support that goes through the firewall and ad welded to the center tunnel inside the car around the shiftrod connector area.
This is the same support that exists on Carrera RS -73.

Someone told me that only early 76 turbos had this support, part of an homologation or a car I cant remember.
Can anyone confirm that this is a 76 only reinforcement (the first picture)?

http://forums.pelicanparts.com/uploa...1284966996.jpg


http://forums.pelicanparts.com/uploa...1284967009.jpg


http://forums.pelicanparts.com/uploa...1284967025.jpg

Sorry for bringing an old thread up, but I just wanted to find out how much wider track width do the 930 trailing arms give you?

I have read some posts that fitting 911R wheels (7-inch) to narrow body 911 require wheel spacers like 15mm or 19mm thick and long studs but I don't like wheel spacers, so I'm wondering if replacing stock trailing arms and torsion tube with 930 ones is a good alternative?

Thanks in advance.

You realize that replacing the arms and torsion tube is about a million times more work than adding spacers? The geometry/kinematics for the 930 are different from a 911 so you might notice some odd handling with the 930 rear but not the 930 front.

I do realise it's a lot more work, but anyway I'd like to know how much wider are the 930 arms? Is it more than 3/4-inch wider each side?

The arms are shorter, but I think the hub might stick out further. If you use 930 arms with the standard torsion tube your wheelbase is shorter and your track width narrower.

Not even possible unless you plan on bending the spring plates.

don't know the actual width difference, but when you add turbo rear flares to a narrow body car with stock arms and use 8x16s, you need 2" spacers to get the tire in the right place.

With the transition of SRP to JWE, another source for the torsion bar pivot boxes is John James Racing

He makes various types:

-raises the pickup point for use with typical 911 aluminum trailing arms on 911 t-bar housing
-raises the pickup point for use with 930 trailing arms on 911 t-bar housing
-raises the pickup point fo use with 930 trailing arms on 930 t-bar housing

Camber Boxes « John James Racing

Obviously not a very useful link..... I think they're slooooowly updating their site. Jim Hendrix does still make them. Local friend source a set from him not too long ago.

Not something you want to do to a pre-72 tub. There are shock alignment issues with the upper mounts and the heat exchangers as well. So, beyond all of the t-tube mounting point issues, a pre 72 tub is just not well suited for it and, the performance aspect is negligible for "most" people wanting to do it.

Thanks for this. So, does a stock 930 use any spacers and if so, what's the thickness?

Stock, rear 930 spacers are 28mm thick.