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Which is best for F1 clutch- normal or race?

Discussion in '360/430' started by 456mgt, Mar 27, 2004.

  1. 456mgt

    456mgt Formula Junior

    Mar 24, 2002
    628
    Cambridge UK
    Full Name:
    Kevin
    Trying to work out whether it's easier on the clutch to drive an F1 Stradale in normal city mode, or engage race. The default setting slurs the shifts, while race dispenses with all that and bangs the next gear in. I can tell you right now that 'race' is much more fun :) I would have thought that it's also the best one for clutch wear, but Manu (Scuderia Systems) and I have a Mexican Bull$hit Standoff going on this one.

    Can anyone resolve it?


    Kevin
     
  2. stradman

    stradman Formula 3
    Silver Subscribed

    Jan 8, 2004
    1,272
    London UK
    Full Name:
    Stradman
    My 2p on this one Kevin. It seems to me that if clutch plate is released more suddenly, as it is in race mode, then although you will experience a perhaps jerkier change, the whole gear change process is over and done with quicker and so there is less time for friction forces to wear down your clutch on the plate. Conversely if the idea is to feather the clutch release to produce a smoother change(i.e. default) you let the clutch go over a longer period of time and so more time leads to longer clutch plate contact/friction forces and therefore quicker wear and tear. But then again what do I know?
     
  3. Brian C. Stradale

    Brian C. Stradale F1 Rookie
    Lifetime Rossa

    Mar 17, 2002
    3,603
    Dallas, TX, USA
    My 2p... I think its a curve...

    A super jerky release means extreme forces are being applied, even if for a short time... not good.
    A super slow release means you are allowing gentle slipping for a prolonged period, generating heat and a lot of rubbing... not good.
    Somewhere in between is optimal... and somewhere in between is where most manual shifters land... though probably few hit optimal too often.

    Ideal, is a jerk-free instant release. How do you do that? Exactly match engine speed to wheel speed (engine-side of clutch to wheel-side of clutch) and then release the clutch fast. The beauty of the F1, with its computer monitoring of both engine/wheel speeds and the ability to blip the engine as needed, it CAN do this.

    However, when you are ACCELERATING hard, you have a problem. For the 100-300 ms that the clutch is disengaged, the car is coasting. That presents a design problem (theoretically, at least)... you must decide whether to optimize acceleration or minimize clutch wear:

    For minimal clutch wear, you'd want to let off the throttle a bit right before you disengage the clutch such that when you disengage the engine-side doesn't speed up or slow down... and then you'd shift, adjust engine RPMs to match, and then engage the clutch... only when its fully engaged would you then re-apply throttle to get the engine pulling the car again... accelerating again. In that way, there is never any slip in the clutch.

    For maximizing acceleration, you do NOT let off throttle before disengaging the clutch... you let the engine keep pulling until the clutch actually separates enough that the engine RPMs start rising too much... similarly, you don't necessarily match the RPMs exactly... you let the engine RPMs be a bit faster, so that by the time the clutch is just starting to come together, you are already getting some pull. But that means some extra slipping both as you disengage and as you re-engage the clutch.

    Now, the question is... what design choices did Ferrari engineers actually make there??

    My guess is that normal mode is going for a fairly smooth and probably is as gentle as you are going to get on the clutch (though may not be minimizing clutch wear completely); while race mode is maximizing acceleration, and thus will likely compromise a bit on clutch wear.

    HOWEVER, I will also guess that the F1, when used properly, is far easier on the clutch in either mode than most drivers are with a manual. The exception is those drivers who drive the F1 like its an automatic and end up putting tremendous wear on the clutch in 1st gear with a variety of low-speed maneuvers that nobody operating the clutch themselves would ever do.

    But in the end, that was just a 2 penny SWAG.
     
  4. thomas_b

    thomas_b Formula Junior

    Sep 15, 2003
    765
    Based on missing facts I never reached a conclusion about clutch wear in sport/race mode for the F1

    The manual differentiates between three modes “torque reduction”, “no torque”, and “torque return” (see attached diagram A, B, C)
    - the time profile for “torque reduction” phase is influenced by the sport mode (on=faster); sport mode is not mentioned in any other phase
    - during “no torque” phase the engine is requested to reach a specific RPM level, i.e. the phase is dependent on car speed and gear request
    - the “torque return” profile depends on requested performance (throttle) and is controlled by the difference between engine / gearbox shaft RPM

    so it seems that sport mode only influences the duration of the torque reduction phase – the other phases are controlled by different parameters – what one should experience is a more abrupt reduction of torque – the driver can control closing of the clutch mainly through the throttle

    note aside – some of the shift behavior improvement in the Challenge cars are achieved by not fully closing the throttle during the shift operation!
     

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