systemmeister
Well-known member
- Joined
- 25 Jun 2014
- Messages
- 324
I found it frustrating that there is no good information out there about how and what to fit in order to get away from the stock airbag wheel, and go with aftermarket version.
So I decided to capture the information in pictures and write a short report for anyone interested.
My original wheel;
I was suffering from poor seating position being 6'6" tall due to the height (or lack thereof) above my knees/legs.
I decided that better reach (and better knee clearance by having wheel nearer my hands) would be my goal.
Furthermore, I had seen eccentric adapters to increase leg clearance yet more.
After some research I realised there was no such thing as a 996 steering wheel adapter boss.
Some further research uncovered some folk using a Porsche 944 boss, however this would need some adapter washers to pack-out the column nut (as apparently the 996 column isn't threaded far enough down....no big deal).
The Momo Boss is a MOM7004.
As you can see - the treads aren't sufficient.....
so I selected some thick washers to pack it out - the first of which must be slightly larger diameter than the threaded part - as you might notice the slightly enlarging shaft at the place where the washer will rest?
Before I set out on modifications, I read up on how to defeat airbag MIL light and bought some resistors from my local Maplins.
I made up a fuse / resistor assembly and had this ready.
It took me a while to work it out, but I knew that the existing steering wheel uses a "clock spring" wiring cassette to pass the airbag and horn wiring from the column/squib to the wheel itself.
I knew this clock spring cassette would have to be removed...leaving a problem about how to connect the horn.
I also then realised that removing the cassette would expose the column stalk switch chassis metalwork to some degree.
Cassette removed....
Wiring connector for horn and airbag - goes to clock spring cassette....
Cut off the wires, leaving a bit to play with.
Insulate the horn earth, and leave other ready to connect (red joiners) - and then connect airbag resistor/fuse to the others. Plug back into car loom / tuck away.
Decided to cover the switch metalwork with some 3M carbon effect foil sheet.
You could use anything similar, or paint it.
For the horn contact, older cars (pre-airbag) used a brass contact strip.
I rummaged through my parts boxes from a stripped Mk2 golf and found an indicator stalk unit which included the centre ring contact.
Three screws and the plastic case was in two halfs.....I binned the stalk and other gubbins, just keeping the bit I needed.
I carefully trimmed the back of it flat.
Soldered on a fly lead and heat shrunk the joint and remaining strip to insulate from earthing out.
I carefully drilled the top edge of the switch plate on the car - carefully collecting swarf with a strong magnet.
Two bolts through the plastic housing using existing holes to fix it - with nuts on the rear.
The trial effect with the squib front offered up.
Eccentric Momo boss adapter fitted.
Raised the wheel about 12mm in the straight-ahead position.
Washers fitted and boss bolted up just fine.
Bought a genuine steering wheel from Demon Tweeks (same place as Boss was supplied).
The finished result;
If you would like to strike a deal with Demon Tweeks - give them a call and tell them you've seen my report on 911UK - and talk to Paul Jones
01978 663054.
I placed the order for my wheel at around 4pm - and it was at my door the next morning!
So I decided to capture the information in pictures and write a short report for anyone interested.
My original wheel;
I was suffering from poor seating position being 6'6" tall due to the height (or lack thereof) above my knees/legs.
I decided that better reach (and better knee clearance by having wheel nearer my hands) would be my goal.
Furthermore, I had seen eccentric adapters to increase leg clearance yet more.
After some research I realised there was no such thing as a 996 steering wheel adapter boss.
Some further research uncovered some folk using a Porsche 944 boss, however this would need some adapter washers to pack-out the column nut (as apparently the 996 column isn't threaded far enough down....no big deal).
The Momo Boss is a MOM7004.
As you can see - the treads aren't sufficient.....
so I selected some thick washers to pack it out - the first of which must be slightly larger diameter than the threaded part - as you might notice the slightly enlarging shaft at the place where the washer will rest?
Before I set out on modifications, I read up on how to defeat airbag MIL light and bought some resistors from my local Maplins.
I made up a fuse / resistor assembly and had this ready.
It took me a while to work it out, but I knew that the existing steering wheel uses a "clock spring" wiring cassette to pass the airbag and horn wiring from the column/squib to the wheel itself.
I knew this clock spring cassette would have to be removed...leaving a problem about how to connect the horn.
I also then realised that removing the cassette would expose the column stalk switch chassis metalwork to some degree.
Cassette removed....
Wiring connector for horn and airbag - goes to clock spring cassette....
Cut off the wires, leaving a bit to play with.
Insulate the horn earth, and leave other ready to connect (red joiners) - and then connect airbag resistor/fuse to the others. Plug back into car loom / tuck away.
Decided to cover the switch metalwork with some 3M carbon effect foil sheet.
You could use anything similar, or paint it.
For the horn contact, older cars (pre-airbag) used a brass contact strip.
I rummaged through my parts boxes from a stripped Mk2 golf and found an indicator stalk unit which included the centre ring contact.
Three screws and the plastic case was in two halfs.....I binned the stalk and other gubbins, just keeping the bit I needed.
I carefully trimmed the back of it flat.
Soldered on a fly lead and heat shrunk the joint and remaining strip to insulate from earthing out.
I carefully drilled the top edge of the switch plate on the car - carefully collecting swarf with a strong magnet.
Two bolts through the plastic housing using existing holes to fix it - with nuts on the rear.
The trial effect with the squib front offered up.
Eccentric Momo boss adapter fitted.
Raised the wheel about 12mm in the straight-ahead position.
Washers fitted and boss bolted up just fine.
Bought a genuine steering wheel from Demon Tweeks (same place as Boss was supplied).
The finished result;
If you would like to strike a deal with Demon Tweeks - give them a call and tell them you've seen my report on 911UK - and talk to Paul Jones
01978 663054.
I placed the order for my wheel at around 4pm - and it was at my door the next morning!