[Question] How much potential gain is there from a pump set back?
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How much potential gain is there from a pump set back?

  1. #1
    Senior Member HomeBlown57's Avatar
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    Default How much potential gain is there from a pump set back?

    I have a 77 brendella 18'6" tunnel pickle. Over the winter I will be setting a new intake. The existing location has about 1-1/4" of glass left in front of the transom. The engine is 1040hp. I am installing a low profile intake.

    My question is: what is the gain in setting the pump back? I have read a lot of the "setback" threads and the question is asked in all of them, but not answered.

    Does it make the boat more stable? It seems that it would be the opposite.

    If someone could direct me to an article that gives answers I would appreciate it.

    Gaining 3mph is not worth cutting the back out of my boat. Gaining 10mph might be worth it. I am aware that there is no formula for inches of setback to MPH gain, but there IS a gain to be had. I am looking for a generalization of what the purpose is.

    If the gain is better acceleration, that would be much more enticing. 0-60 or 40-100 acceleration would much more valuable to me than 3MPH.

    If tuning the pump becomes easier that may be worth it as well.

    It seems like you would need less shoe if the rear edge of the intake opening has no boat behind it.

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  3. #2
    Senior Member 79sleek's Avatar
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    Default X2

    X2 ????????? Answers?????? Advice???????

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    B1 Racing cs19's Avatar
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    With only 1-1/4 amount of setback I wouldn't expect to set the world on fire, it certainly cant hurt though.

    Are you setting it back just to set it back or are you doing it to get a pop off valve to fit? You might consider leaving some of the boat behind the intake if your not doing a pop off. Its much much stronger.

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  6. #4
    Senior Member HomeBlown57's Avatar
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    If I were to cut the hull I could move the intake about 4", if the rearest (if that's a word) portion of the intake opening is flush with the transom.

  7. #5
    Senior Member HomeBlown57's Avatar
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    No pop off valve. For now anyway.

  8. #6
    Senior Member HomeBlown57's Avatar
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    Bump

  9. #7
    B1 Racing cs19's Avatar
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    Quote Originally Posted by HomeBlown57 View Post
    If I were to cut the hull I could move the intake about 4", if the rearest (if that's a word) portion of the intake opening is flush with the transom.
    Post pics

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