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"Double Clutch" Question

Discussion in 'General Automotive Discussion' started by karmavore, May 12, 2004.

  1. karmavore

    karmavore Formula 3

    Dec 29, 2002
    1,641
    Maryland
    Full Name:
    Luke Colorado
    Correct me if I'm wrong...

    Procedure: Clutch-> Move stick to neutral-> Release clutch-> Throttle to RPM for Speed/Gear combo -> Clutch-> Move stick to gear-> Release clutch.

    Reason: To match in/output shaft speed in no syncro cars. Also, saves synco ware on syncro'd cars?

    If that's true, why depress and release the clutch twice? why not:

    Clutch-> Move stick to neutral-> Throttle to RPM for Speed/Gear combo -> Move stick to gear-> Release clutch??

    Seems faster.

    Luke.
     
  2. Aureus

    Aureus Formula 3

    Its called "double clutch" for a reason ...
    The first one you described is double clutching, the second is just shifting normally.
     
  3. Forza1

    Forza1 Formula Junior

    Mar 20, 2004
    484
    California
    Full Name:
    DC
    Correct me if I'm wrong, but I'm sure double clutching is only used for downshifting...?

    At any rate, the first procedure you listed was double clutching, and rev matching together. I normally do both like this when driving around. Some race cars, and older cars require double clutching because of the lack of synchro's, like you said. The second procedure you listed is just rev matching. This only helps half of the battle(it's still better than not doing either), but you must double clutch also if you want no synchro wear, and liquid smooth shifts.


    Abstract: Double clutching spins one half of the two spinning pieces to the right RPM, rev matching spins the other half to the right RPM, both together is the goal.

    The correct procedure for double clutching and rev matching is as follows:

    See turn > clutch in > shifter to neutral > clutch out(first half spins up to speed) > clutch in > shifter to gear > blip throttle to match RPM's(spins the second half up to speed) > clutch out > smile :)


    Double clutching procedure:

    See turn > clutch in > shifter to neutral > clutch out > shifter to lower gear > clutch out


    Rev matching procedure:

    See turn > clutch in > shifter from gear to lower gear > blip throttle to match RPM's for the gear > clutch out


    At any given time, I will always rev match, and 90% of the time I'll double clutch while I'm at it. Not only is it good for your transmission, but it is also fun to do, and if done right, you will shift really smoothly.

    HTH.



    -DC
     
  4. UroTrash

    UroTrash Three Time F1 World Champ
    Owner Consultant

    Jan 20, 2004
    33,217
    Purgatory
    Full Name:
    Internet Poseur
    I think this thread would get more response if it was on the "Vintage" forum.
     
  5. karmavore

    karmavore Formula 3

    Dec 29, 2002
    1,641
    Maryland
    Full Name:
    Luke Colorado
    If you're rev matching why do you need to use the clutch at all during sifting? I understand (from experience) that releasing the clutch releases the pressure on the dog teeth and allows you to move into neutral, but I don't understand why? Also, if I'm in neural and I rev match and theoretically I have the input, lay, and output shafts all spinning at the same speed shouldn't I just be able to slide the dog teeth into place with out the clutch? In fact, doesn't releasing the clutch cause my RPM to drop and through the the shafts out of sync?

    http://auto.howstuffworks.com/transmission4.htm

    I love How stuff Works.

    Thanks for the help!

    Luke.
     

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