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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?

    http://www.youtube.com/watch?v=uTX06hUG3pw

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

    #2
    The only thing that I can distinguish is he's saying "too fast" a few times.

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      #3
      He does not talk about it in that video. I did watch this video

      https://www.youtube.com/watch?v=X1BXzunn1bk

      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.

      Comment


        #4
        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

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