drnick

i havent seen the linkages between the regular shifter and the transmission but i was wondering whether it would be possible to convert the stick to a cable type mechanism, like on a mountain bike. if this were possible then it could be positioned behind the steering wheel with paddles for up and down without too much dificulty (in theory).

how much pressure is required to move the shift lever at the box, and how much movement is required - anyone know?

drnick

looking at some pics of the transmission shows that it is in fact cable operated and the range of motion seems reasonable, not sure how much tension is required to move the lever, or how positively it engages with each selection. thinking further and the idea of a long cable linkage is unatractive, perhaps a servo driven shift - the 2-3-2 shift would be difficult though...

BrianG

I just replaced the shifter cable, and the transmission can be shifted by hand, by grasping the cable- lever and twisting, so the force required is reasonably low..
Drag-racers commonly use "air" or "electric" shifters, I'd bet you could utilize that technology for this concept.

drnick

more appealing still would be to upgrade from 4 to 5 spd auto with an electronic shift, it must be possible..

BrianG

anything's possible if you can write the cheque!!

Barry Johnson

I've heard of this before, but no one ever found anything out on it. It would be a great experiment that I'd be willing to do on my S4 auto.
Is there an auto box with more gears that could fit and be used in our rear-transaxle cars? Do the C5 Vettes have an auto box that could be made to work?
And, how would you make the paddles spin with the steering wheel, without disrupting the linkage?

BrianG

The tranny's going to be the hard part. The paddles could use horn technology.......... "ring & brush"

Jessa

Could a modern Tiptronic be adapted to a 928? Maybe one out of a 968?

drnick

there was a thread and steve c chimed in suggesting another iteration of the mercedes box although there would be some cutting to the transmission tunnel required. this would be such a good upgrade as there is too much space between the first three ratios.

Z

Most of what's been mentioned in this thread is already being worked on. There's an S4 A/T with eight forward speeds that's been driving around for months already. No modifications to the stock body of the car were needed. Having ridden in the car, I can say that it's definitely very interesting. The paddle shift electronic/pneumatic shift control is expected to be finished when the car comes out of hibernation in spring.

adam928

On a track event this summer I met this guy who has built a similar solution on his Camaro. He and his friend (who where an car computer programmer of some kind...) re-programmed some of the software and built a simple "tiptronic-solution" with paddles.

Im not sure if the same technique can be applied to the sharks but if I understood it correctly the mechanical work was quite simple. They had in some way tapped into the signal from to the transmission telling it to shift up or down.

I tried to find some images of the car but only found this one:
http://my928.kicks-***.org/steph/ind...=displayImages

The guy also have a dual compressor solution tucked in there that might be interesting

Barry Johnson

Hey Z, how does it shift? Paddles you say?
Having 8 gears (4 real, and 4 pseudo gears?), how is the acceleration?
Find out more if its able to be disclosed at this point.

drnick

z, any more details that you can share?

Jim bailey - 928 International

Has to be a overdrive / underdrive unit turning a stock transaxle. The 4 plus 3 corvette boxes were a combination of a 4 speed manual trans with automatic two speed overdrive. This iteration might be an electrically shifted manual two speed into the stock 4 speed automatic. That can give you some unusual gear ratios 1 st ,1st with overdrive,2 nd ,2nd overdrive,3rd ,3rd overdrive etc. BUT first with overdrive might be higher than 2 nd or very close. Takes me back to the 1960 XK150 Jaguar 4 speed manual with electrically shifted overdrive, flip lever on the dash.

Tony

We used to have an old Mark X Jag in England, it had that switch as well.