One of the things I miss the most from my previous p-car, a '81 911 SC, was the Momo Prototipo steering wheel. I have had paddle shifters on my stock 4 spoke steering wheel for a while now, and even though it's a far, far better feeling to shift with compared to the stock buttons, I really wasn't completely satisfied.
So, the question naturally appeared: Would it be possible to add paddle shifters to a Momo Prototipo without it looking terrible? I had to find out. As Clarkson says - how hard can it be?
Here's the previous setup:
I ordered the steering wheel and a hub kit from ebay. The hub kit included the airbag resistor I needed, and also a gizmo going behind the wheel to retain the function of the horn. I later discovered that I probably don't actually need it as I hacked into the clock spring wiring.
Yeah, the clock spring... I found some threads online where it was claimed that there is a Momo hub for Porsche which retains the clock spring, and I searched and searched for it but couldn't find any anywhere. So, a hack it would be...
And here comes the ghetto part. Google revealed that many after market paddle shifters (and NOS buttons, apparently) use a 'curly wire' or spiral cord, like the ones we had on the old telephones, so I soldered 4 connectors at each end of such a cable. It would perhaps not be pretty, but I thought it would work.
Following the wiring to and from the clock spring, from the connectors in the dash through to the wheel, I figured out which went to up, down and ground (and horn - more about that later) buttons, and soldered connectors in place. The green wires in the yellow connector are for the air bag, and I soldered short wires at each resistor leg and stuck them in the green connector in the dash, and secured it with electrical tape. This was for me the most scary part, as if the airbag light comes on you need the Duramatric to kill it (after what I've read).
Now, how do I mount the paddle shifters to the wheel? The shifter are AMG ones which I found on ebay. (I followed a how-to on Rennlist where I got the part number for them). They are mounted from the inside, which was a possibility with some washers and a screw, but that wouldn't be nice.
Also, the curved metal tabs in the corner move inwards when the paddle is pressed, so it can't be mounted flush to the wheel, so I needed a spacer. I looked around in the house and my eyes fell on my 4-year-old's marble game. I dremeled thin 'cylinders' which I painted and Tec-7'ed to the paddles. Since the wheel has holes, and the underside of the shifters aren't particularly pretty, I put grip tape from the underside of the holes. Looks better than duct tape, and has a nice texture. Then I Tec-7'ed the units to the actual wheel, carefully setting the placement.
The shifters hav a lip going around the unit, so I also used thick grip tape to camouflage the MacGyver'ed mounting.
Then it was time to put all wiring and connectors inside the hub, mount it in the car, cross the fingers and hope that no airbag light comes on...
And it was a success! Well, almost... Airbag light did not come on, but as soon as I touched the negative battery terminal to the battery the horn sounded. I had shorted the horn... somewhere... I had to think a little, but realized that one of the two wires I thought went to the ground in the wheel, actually is for the horn... DUH! Connected that one to the horn button instead, and then... YES! Success!
Now, I have a vacuum leakin the oil filler tube, so after reconnecting the battery it sputters terribly and won't idle properly. I really have to swap the oil filler tube, but I MacGyver'ed than one for now and have to drive for a bit for the car to 'relearn' itself. (I had the same issue last year). Thus, I haven't yet fully enjoyed the feeling. But the up an down paddles shift as they should.
I thought about painting the paddles black, but they match the trim rings around the instruments, so I let them be. For now.