Results 1 to 4 of 4

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

  1. #1
    Senior Member Joe-MN's Avatar
    Join Date
    Sep 2009
    Location
    Twin Cities, MN , USA
    Posts
    324

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

  3. #3
    Senior Member maddog's Avatar
    Join Date
    Feb 2004
    Location
    Clemson, SC
    Posts
    148
    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.

  4. #4
    Senior Member pfcs49's Avatar
    Join Date
    Aug 2013
    Location
    NW NJ ***********T12 cmplt since 95
    Posts
    1,618
    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; 11-03-2014 at 09:39 PM.

Similar Threads

  1. FN ps-90 High speed gear chest rig video
    By SethO in forum Recreation, Sports, Travel, & Hobbies
    Replies: 6
    Last Post: 05-13-2012, 09:28 PM
  2. Old Interesting Video
    By Schmeky in forum Cure
    Replies: 3
    Last Post: 05-23-2010, 12:17 PM
  3. interesting video
    By cypresss in forum Cure
    Replies: 5
    Last Post: 07-17-2008, 04:53 PM
  4. interesting video
    By adi chicago in forum Cure
    Replies: 1
    Last Post: 06-22-2008, 03:04 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •