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  1. #1
    wakeboardmuppet's Avatar
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    HKS BOV query ??

    I've fitted an HKS Bov. To test it I took a T off the vacuum pipe between the inlet manifold and the sensor, fired up the engine, and the BOV dumped air perfectly. I then replaced the T with a 4 take off vacuum manifold (similar to R3_Killa) so that I could have a boost gauge as well. The engine fired up alright, but the blow off valve didn't dump air and the boost gauge barely read into + under throttle, although on tickover it was running good vacuum. I disconected the vacuum manifold and the dump valve worked perfectly again.

    The vacuum manifold has a 3/4" bore through it and is about 4" long. Is it leaking, or is there too much volume for the engine vacuum to empty it and then pull the diaphram across in the dump valve.

    Any ideas or thoughts
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  2. #2

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    The engine doesn't start making boost until 5500 or so RPM's.

  3. #3
    wakeboardmuppet's Avatar
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    Quote Originally Posted by SHOdude View Post
    The engine doesn't start making boost until 5500 or so RPM's.
    I only have to throttle it a little bit, and when I place my hand over the BOV is dumps a lot of air when I throttle off - until I connect the vacuum manifold that is???

  4. #4
    SHOBiz's Avatar
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    Quote Originally Posted by wakeboardmuppet View Post
    I only have to throttle it a little bit, and when I place my hand over the BOV is dumps a lot of air when I throttle off - until I connect the vacuum manifold that is???

    You are correct, you should be able to even just hit 2500 RPM or so and feel the air getting dumped. I would replace the manifold with a T and be done.

    You can always use a double t (or is that teets?) for the guage to be added.

  5. #5
    wakeboardmuppet's Avatar
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    Quote Originally Posted by SHOBiz View Post
    You are correct, you should be able to even just hit 2500 RPM or so and feel the air getting dumped. I would replace the manifold with a T and be done.

    You can always use a double t (or is that teets?) for the guage to be added.
    I've just been looking through Jerry's SHO Boost Gauge install, and there was a comment on there that the BOV take off should not be run off a vaccum manifold set up like I've done. Seeing as this is the most important, I'll do as you suggest, bin the manifold and tap the inlet specifically for the BOV. I'm not gonna ruin the supercharger clutch after being off the water for 4-5 weeks already

  6. #6
    hitman's Avatar
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    Quote Originally Posted by SHOBiz View Post
    You can always use a double t (or is that teets?) for the guage to be added.

  7. #7
    SHOBiz's Avatar
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    Quote Originally Posted by wakeboardmuppet View Post
    I've just been looking through Jerry's SHO Boost Gauge install, and there was a comment on there that the BOV take off should not be run off a vaccum manifold set up like I've done. Seeing as this is the most important, I'll do as you suggest, bin the manifold and tap the inlet specifically for the BOV. I'm not gonna ruin the supercharger clutch after being off the water for 4-5 weeks already


    Rather have your S/C working than a gauge

  8. #8
    hitman's Avatar
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    If you only have trouble when using that multi vacuum port adaptor then I would say the adaptor is the problem.

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