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Hand control video - interesting, not quite sure what is all going on (for gear heads

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    Hand control video - interesting, not quite sure what is all going on (for gear heads

    Like the title says, interesting. This is in an early Porsche with a Sportomatic transmission, I think. You can see him shifting a few times early on, but after that it appears to be just throttle and brake. I can see the twisting for throttle, and pushing forward for brake, but he is also moving the control downwards early on and there is a little hook for his middle finger. Sportomatics do not have clutch pedals. Anybody understand German who can explain ALL that he is doing?

    Manfred Huber Perez Moreno
    Better to remain silent and be thought a fool, than to speak and remove all doubt.

    The only thing that I can distinguish is he's saying "too fast" a few times.


      He does not talk about it in that video. I did watch this video

      At the 2:30 mark he says pushing down engages the clutch, forward the brake, twist the throttle, and the hook is the hand brake.


        I watched this and another of his videos. Here's what I think.
        The main control has a"knee" joint in the middle. When it is @180* (like a straightened leg) and is pushed forward, it operates like any push to brake deal.
        Obviously the end of the control is a twist throttle; sometimes i see a big knob, but I suspect other times it is "L" shaped (I would do it that way)

        Sportomatic Porsches and Automatis Stick Shift VW Beetles have nearly identical systems. A vacuum control valve is controlled by a solenoid; when the control valve applies vacuum, the clutch (a fairly normal single plate dry automotive type, but in the transmission housing, just behind the bell housing) de-clutches the system. In the bell housing is a torque convertor which allows full stops with clutch engaged/engine running. You can select any gear and drive off from a stop, but acceleration is compromised in higher gears; because the convertor multiplies torque, the lowest gear is absent; (so Beetles have 3 fwd speeds)
        There is fore-aft play in the shifter, centered by spring pressure; when the lever is pulled or pushed, it closes a microswitch in the base which commands the vacuum control valve to disengage the clutch (quickly). There is also a neutral switch in the shift linkage and when in neutral the clutch disengages. The vacuum control valve adjusts the rate of clutch application based on a vacuum modulater which sees a load signal from the carburetor or throttle body; part throttle/low load-slow; high load-quicker and quicker depending on load.

        I think he has eliminated the microswitch in the shifter-base, and rigged it so when he folds the brake/throittle lever down, it de-clutches. I think he only shifts once and then runs in a single gear, but I might have missed a shift.
        I don't recall which video, but it looks like he can push the brake forward and engage some kind of latch or line-lock to provide a parking brake function.
        At 20-28s of first video he fiddles with a knob normaly above his finger; it may be a way of trimming his vacuum signal to control his clutching dynamic or it may be un-related to hand control functions.

        A couple thoughts: Member "MrSporto" has a VERY nice Sportomatic 77 911 Carrera 3.0 he is ready to sell now that he's become a family man! PM him. He's in N NJ
        I raced an 88 Golf GTI converted to hand controls using, among many things, the shift base/microswitch, vacuum servo, and vacuum control valve from a VW. It is astonishing how well the clutch worked using the VW stuff!
        It would almost launch from stopped/idle without stalling-it requires just a smidge of gas. And if I gave 2500rpm and released the clutch switch (by my throttle lever on brake handle), it would light up the slicks! And, anywhere in between-like on a hill/stopped, it would feed the clutch out just like my foot did in the old days, and I would modulate the throttle accordingly. Unfortunately, the 3 years I raced it (01-4), I never got around to taking pictures of the controls or sticking a video camera in the car-I was having too much fun till I wrote it off a RA
        Last edited by pfcs49; 3 Nov 2014, 9:39 PM.
        69yo male T12 complete since 1995
        NW NJ