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Thread: PV Question

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    mrbtd's Avatar
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    PV Question

    2001 GP 12r.

    I have read a bunch of info on the power valves and know at minimum I need the wave-eater clips.

    Trying to come up why a Gas valve and Performance valve is available ? Any performance advantage ? Looking to build a hard accelerating ski

    What controls the gas valve ? I know on the doo's there is a solenoid.


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    xyzyx00's Avatar
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    Last edited by xyzyx00; 09-29-2006 at 07:33 PM.

  3. #3

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    The mechanical valves with the servo motors have a more metered or controlled accelleration from bottom to top.... it is not completely smooth, but smoother than the gas valves.

    Down side: they can destroy a piston. They open and close at the same time even though timing curves may be different at different rpms and different engine loads for each cylinder which could potentially put your engine at risk. Servo motors fail.

    The gas valves are very hard hitting beginning from I would guess 5400 to 5800 rpms all the way to the top. I love the feeling when I accellerate out of the turns.
    The gas valves are pressure sensitive and operate independently of each other. From my perspective, they are safer for your engine because they will not drop on top of your piston due to their design and they are capable of responding to load and timing changes independently.

    Down side: they can leak pressure, and for that reason you can loose considerable rpms.... 200 is not uncommon. They are expensive and not necessary to get high speeds out of our Yammi's. They are something else that has to be "tuned".

    I am pretty sure there is no performance gain on the top end of perfectly tuned gas valves vs. well set up mechanical ones, but do not know this for a fact. I do believe gas valves are much safer and to my thinking easier to work with and so I use them.

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