James Bailey

Kids come from jumping on something else ! Plus spending that kind of money on a transmission for a car which already has a transmission might seriously detract from your chances of having children.......

Carl Fausett

The Chevy Torque-tube to Porsche 928 bell-housing adapter has arrived, here are a few pics.

I designed it to be a slip-fit into the Chevy TT, then we can locate the transaxle ideally and adjust the length of the TT as needed. Then of course it will be TIG welded in position.

Trying hard not to loose the feature Porsche gave us where we can service the clutch without removing engine, TT, or transaxle. When I am finished, we will still have that same ability like we do now.

Mongo

Impressive!

xschop

Custom 23 spline or 26 spline input shaft?

Dinsdale Piranha

Great work. How will you adapt the input shaft ? Does the driveshaft have to be balanced ? Will you use the original rear crossmember??
Can't wait for the next episode of " As the six speed turn's". Once again, Kudos on the progress. Fantastic work!!

Carl Fausett

This appears to be the only section of the Chevy aluminum driveshaft that I need to have customized.

This is the most forward section of the Chevy driveshaft - from the rubber (now polyurethane - see earlier post in this thread) isolator forward through the clutch and into the pilot bearing.

In our design, this will be quite short, terminating in an end identical to the stock 928 driveshaft. That way we can use the stock stub shaft and slide-collar on this installation and continue to provide the ability to service the clutch without removing engine, TT, or transaxle. That's a feature I do not want to lose.

The stub shaft and slide-collar have not been a failure point for us so I have no concern over putting them back into the driveline. They seem to be good through our output levels.

I already have a manufacturer of driveshafts who has looked at this and can make it. He's just waiting for me to give him the length dimension.

Thank you for your kind comments, much appreciated.

atb

That last section to get you to the stock intermediate shaft looks to be the keystone in this whole set up Carl. You get that worked out and it looks like you are good to go as far as getting drive from the crankshaft to the rear wheels. Nice Work!

slate blue

Carl, the problem I see with Porsche's sliding shaft, is that as HP/Torque increases, this is the weak link. My car with only 400 HP but reasonably wide rear tires (295) broke that shaft or more accurately cracked it. I am not the only one to do so. You may be aware of members of the 928 racing forum that have also cracked it. I personally would do away with it and have the one shaft all the way through.

Is there a length problem in doing that? Is the corvette torque tube and gearbox shorter or longer that the 928's driveline? I think by removing this weak point this is a further upgrade.

Also how does the drive axles line up with the hubs in relation to your conversion go. If we go all the way back I think to 1981? Porsche improved this alignment by moving the gearbox forward 30 mm. Wondering how yours is given the greatly increased power numbers you are pumping out versus the 1981 model. Or is the position of the Corvette transaxle dictated by its size and shape and it goes where it can fit?

928mac

Very cool Carl and some very nice looking parts.
I can not see me needing or affording one but I wish my car had an extra gear.
I also wish it had a SC to make it need the bigger trans.

FBIII

One of the few areas where Porsche really got it right in my opinion is with our clutch. The dreaded clutch job for us is a simple task. iIf the clutch stubby shaft is the weak link that would be fine with me. Look at the alternative and what a pain in the *** a clutch replacement would be. I recently sold a 944 Turbo S just because I dreaded a pending clutch replacement. Having that shaft be the weak link might be a good thing. If it were eliminated or strengthened what would the next weakest part in the driveline be that would fail? Certainly something more costly and difficult to replace.

Carl Fausett

I haven't seen the stub shaft or the sliding coupler as a weak point yet. And I poled Mark Anderson for his break-points as well. I still feel the benefit of being able to service the clutch without removing the trans or the engine out-weighs the possible failure point.

As to the other questions... how far forward we are mounting it, etc, I need to get the car back from Bonneville first (I'm using the stock G28-13 at Bonneville) then we will be doing final fitments of the trans and torque tube to the car.

frankle951

Nice job Carl, you have my vote, for King Shark !!!!!

Koenig-Specials 928

Any updates Carl? How's this project going? Are you road testing a completed install yet?

DZGunner

bump

17prospective buyer

Wow sweet, the Corvette TT is aluminum! I thought the steel one in the 928 was steel for rigidity though? Choosing rear end ratios for acceleration is awesome about this!