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  1. #1
    GDM's Avatar
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    so , is it ok to block off the bov ? ? ?

    i know this thread has been done before but some time has went by and i think we should hear some new info



    it seems there was some conflicting stories on wether or not it was ok to block it off , if you have the bov blocked off tell us how many hours you put on since blocking it off


    also if you blocked it off and have a boost gauge added , does the boost spike under a hard turn or when on rev limiter due to jumping out of the water

    thanks in advance

    .


  2. #2
    I can tell you this,since I hooked up a digital boost gauge on mine a couple of weeks ago I have been playing with the pop off valve and have adjusted tighter and tighter until it won't go no tighter and it changed nothing. Same boost has it was before I started. From what I can tell it won't make any difference in boost if you block it off. I still don't quite understand the purpose of it. You can't over boost a positive displacement blower like the one on the Ultra. It moves the same volume of air with every revolution of the engine weather its turning 10 rpm or 10,000. The pulley ratio is what sets boost pressure. Want more pressure,overdrive the supercharger more. Less pressure, underdrive it.

  3. #3
    Speed Junkie UnleashedBeast's Avatar
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    and it I remember it correctly twin screw superchargers installed on V8 don't have a bov (could be wrong in some cases i'm unsure). The boost PSI was directly related to RPM. The smaller the pulley, the faster the screws turn, and the more boost they create. The BOV would be worth nothing more than a pressure relief when the throttle closed suddenly......unless it was set to lose and it bled off boost prematurely.

  4. #4
    mitch ochoa's Avatar
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    Quote Originally Posted by GDM View Post

    also if you blocked it off and have a boost gauge added , does the boost spike under a hard turn or when on rev limiter due to jumping out of the water

    Would also like to know if anybody checked the boost levels when the throttle is shut or opened suddenly..

    Here's an exact text from Kawasaki technical data regarding the use of two ABVs:

    "To ensure ideal intake air pressure, not one, but two ABVs (air bypass valves) are used. A vacuum ABV is used to balance air pressure upstream and downstream of the throttle body. It works mostly at low and medium rpm. A second, regulatory ABV(
    PLASTIC BOV) aids the vacuum ABV in preventing over-boosting when the throttle is shut (or opened) suddenly. Should the system’s specified maximum pressure be exceeded, the regulatory ABV is activated, allowing air to escape."



  5. #5
    GDM's Avatar
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    Quote Originally Posted by turbodave View Post
    I can tell you this,since I hooked up a digital boost gauge on mine a couple of weeks ago I have been playing with the pop off valve and have adjusted tighter and tighter until it won't go no tighter and it changed nothing. Same boost has it was before I started. From what I can tell it won't make any difference in boost if you block it off.

    so let me know if i am getting this corresct . when you first put your boost gauge on , you were getting over 11 lbs of boost even before you ever opened the bov and tightened it .

    then you started tightening the bov and gained no boost . is this correct


    i just got my r&d boost gauge plate/adapter , today i need to go buy a boost gauge from the local speed shop


    i cant wait to see what mine is doing . i hope i am down on boost . it seems i am down on rpm's a bit


    .

  6. #6
    If your regulatory valve is operating correctly, blocking the valve will do nothing. Only if the valve on the intercooler is loose it will cause problem. Under normal working condition, the valve will always be closed and bleed no air.

    As for Kaw. technical thing, it is bunch of BS as each valve is for different purchase. One is open via vaccum while the other by boost.

  7. #7
    Silence! I Keel You! earthshaker's Avatar
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    An idea came to mind is to put a balloon over the bov outlet.

    That would indicate leaking, needs adjustment, or if it does ever "pop off" as it is meant. Not very scientific, but a good indicator if you have a problem. You might even consider a check valve before the balloon or creatively mark the balloon to see if it ever expanded.

    I've had no time to devote to my ski.

  8. #8

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    Quote Originally Posted by earthshaker View Post
    An idea came to mind is to put a balloon over the bov outlet.

    That would indicate leaking, needs adjustment, or if it does ever "pop off" as it is meant. Not very scientific, but a good indicator if you have a problem. You might even consider a check valve before the balloon or creatively mark the balloon to see if it ever expanded.

    I've had no time to devote to my ski.
    That is a very interesting and cleaver idea. I will do that a week from now when I get back from vacation.

  9. #9
    mitch ochoa's Avatar
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    BOV

    WOuld like to know if anybody checked boost while running WOT on very choppy waters. What levels do you see when the ski jumps thru the air and revs high due to zero water resistance on the impeller..


    Mitch
    Last edited by mitch ochoa; 06-14-2007 at 09:18 PM.

  10. #10
    GDM's Avatar
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    mitch it sounds like you are on the same page as me , you want to know what the real deal is with the bov and if it is safe to block it off for an aggressive rider .


    im on and off the throtle alot in rough water and am wondering if you let off the throtle fast where does the boost go ?

    is the bov constantly blowing off pressure while jumping waves and letting on and off the throtle ?


    or is our bov just a safety that isnt constantly blowing off while jumping and turning hard ?


    .


    .

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