My daughter's boyfriend had a bad motorcycle accident and had his right leg amputated. Now he has a hankering for a 944, manual, not auto. Preferably turbo, ect etc etc

Does anyone have any bright ideas about a hand operated clutch set up?

- Electric: pulling / releasing a gear shift mounted finger / thumb lever to modulate some electric ram that would then operate the standard hydraulic clutch system, or

- Hydraulic: maybe using power steering pump to provide pressure to activate the clutch. Or some add-on pump to an existing belt? (Don't want to lose the a/c pump - too hot in Queensland in summer tyo not have a/c)

Don't want to reinvent something if something's already been done. Also don't want a clumsy set up. Got to be 'slick' for track days.

If we can get this sorted out conceptually we'll then start looking for the right car.

Thanks

Dave

 

I dont think this has ever been done on a 944. The best thing to do it my opinion would be to have something on the shifter, like a trigger or a push button.

From there I would try and keep the hydraulic system in tact. This will make it easier to maintain the car as no custom parts would be needed. You would then need something electric to push the master cylinder push rod in.

You could also try some sort of idea, like how the cruise control works (using a servo motor with a cable to pull the pedal down), keeping the clutch pedal there so that others could still drive the car without having to adjust. I think this would be the easiest way. All you would need to do is fab up a way to attach a cable to the pedal, then find some way of electronically pulling the cable. Come to think of it, you might be able to use a 944 cruise control motor and cable.

It might be easier to do in an N/a 944 as the clutches are really soft, a turbo, especially modded, might be a little harder.

 

Sportomatic?

Edit: let me elaborate - sportomatic was Porsche's early alternative to a manual. It was an electrical solenoid that actuated the clutch when you touched the gear lever. You'd ground out the shift lever (maybe there was some kind of switch), which would disengage the clutch, you'd shift gears, then, when you took your hand off the shift lever, the clutch would re-engage.

 

Whoa neato I didnt know they made that!

 

the sportomatic was only on the 911/912 and 1 or 2 914s though..it was vaccuum operated too if i recall.

has he thought about a 968? didnt they have the tiptronic? so he could still shift, just without the complications of a hand clutch.

another option is to use pneumatics with compressed air or nitrogen tanks. I know this is a popular thing for paddle shifting race cars...only issue is that you have to refill the tank.

 

If his right leg was amputated, isn't it the gas pedal you need to rig? although I can't see using a foot clutch and needing to hit the brakes. Are there vehicle converters in AU that make up cars for paraplegics etc?

 

Hello,

A few years ago I instructed a student who was paralyzed from the waist down. He drove a MAzda RX 7 turbo, manual transmission. The car was modified for hand control of the throttle and brake. The clutch was operated by a pneumatic system. He pressed a button on the shift lever that operated a solenoid that caused a pneumatic ram to press the clutch pedal. The ram would bleed air for a second or two, long enough to allow him to shift.

The system seemed to work well and the driver was good.

Sorry, but that's all I know.

Barry

 

I think this is a great idea, though I second the point about the NA (instead of Turbo) because of its soft clutch. Alternatively, I've heard that the Centerforce clutch for the Turbo is fairly light, but I don't know whether it's still available.

If he drives with his left leg, I think it would be worth reconfiguring the pedal positions a little -- discard the clutch pedal, and move the brake and gas over to the left with extensions, since he would have to be twisted at the waist to properly control the gas, and cornering hard could cause him to be off balance.

Would it really be that important to keep the car drivable by others?

 

Hi all and thanks for the suggestions - keep the ideas coming!!

Even though he's lost his right leg I think it still needs to be the clutch that is hand operated so that he can brake and change clutch at the same time. A 968 tiptronic might be the way to go, but a 968 is out of his price range. Yes, the sportmatic type arrangement is worth looking into - electric rather than air / hydraulic appeals because then the clutch can be engaged / disengaged with the ignition on / engine off. Having to 1st start the engine to then activate the clutch could be problematic. I've been looking at 'linear actuators' - electric rams that can be advanced / retracted with a simple toggle switch.

So I think the next steps are to further investigate 'sportmatic' and 'linear actuators'.

Does anyone know how much force is needed to move the clutch diaphragm? And how far it moves from fully engaged to fully disengaged?

Thanks all,

Dave

 

You mean pressure plate?

My hunch is the slave cylinder moves about 3/4" and probably exerts a few hundred lbs of force.

 

Hi Van, yes, I did mean pressure plate (it was 3.30am here when I typed that!!)

Dave

 

Personally, id tell him to wait and save for a Tiptronic 968. The price difference to a manual 944 will be eaten up quickly by sorting out the clutch control system.

There are pre made systems that can be found.

http://www.apracing.com/info/index.a...on+System_2954

 

theedge,

Here in Oz a 968 tiptronic is in the order of $29,000. A 944 NA - say '86/87 is in the order of 8-9,000. Yes, if he could afford a 968, or is likely to be able to afford one sometime soon, I'd agree. But unfortunately, having been out of work for a year recuperating, and needing a vehicle soon, and wanting a decent sports car, a 944 is a prime option. I guess he could go for a 3-sp auto and later convert it - but I think in the end that would be more trouble and effort than sorting out a manual clutch option.

Thanks for posting the link, I'll have a look at that.

Dave

 

Motorcycles have power assisted clutches you work with your hand. I'm seeing some sort of hand grip clutch rigged to work with the current slave. Would require fabrication and skill i don't have, but I don't see why something like that couldn't be done. Or...buy something tiptronic.

 

he might be better of getting a boxster no offense. although he likes the 944, you could get a 97-00 boxster NON S in triptronic for around 11k or so. which would be WAY cheaper than a 968.....the way i see it is the boxster is an updated 944.

i think he would be better off with a boxster in the long run as long as he gets the porsche shop to look it over first for RMS issues....

it would be newer, a littler bigger engine! and their tiptronic is way better than the technology of the 80's. quicker shifting!

buddy of mine in town was born with left leg issues, and cant move his left leg, he swore by with boxster!