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  1. #1
    urdripn gomzi4629's Avatar
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    What Makes MPH. HP OR RPM

    i everyone i want to build a ski but i just want to know what make u get the mph is it RPM or HP

    if its rpm how much rpm will a ho pump or a seadoo pump take or what is the best pump to use thanks guys


  2. #2
    MPower's Avatar
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    Well RPM gives you HP, so they go hand in hand.

  3. #3
    Lake Mead Bum & BTLS Mark starflight's Avatar
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    Quote Originally Posted by MPower View Post
    Well RPM gives you HP, so they go hand in hand.
    I was thinking you need more horse power to get more rpm. And more rpm gets you more speed.

  4. #4
    deansta's Avatar
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    gpr hull+4 tec rotax=mph



  5. #5
    MPower's Avatar
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    Quote Originally Posted by starflight View Post
    I was thinking you need more horse power to get more rpm. And more rpm gets you more speed.
    HP = TQ X RPM / 5252

    You need torque and RPM to make more HP. Torque is pretty much a constant at 75-90 ft/lb per liter of displacement (unless you add FI). RPM can be changed drastically with different internals, camshafts, porting, etc etc. As long as the motor is set up so you're still making decent torque at higher RPM you will make more power.






  6. #6
    urdripn gomzi4629's Avatar
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    ok well what i have is a motor out of a gsxr its 1000cc its got about 170bhp n about 300plus turbo charged it revs to about 15000rpm n im thinking of putting it a xpl cause i have a spare hull or just get a gpr hull n put it in what do use think. and well a seadoo or ho pump cope with that rpm

  7. #7
    Greenhulk Grasshopah (DRC) HallPass's Avatar
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    Quote Originally Posted by gomzi4629 View Post
    ok well what i have is a motor out of a gsxr its 1000cc its got about 170bhp n about 300plus turbo charged it revs to about 15000rpm n im thinking of putting it a xpl cause i have a spare hull or just get a gpr hull n put it in what do use think. and well a seadoo or ho pump cope with that rpm
    your going to have to seriously do some fab work to get the cooling setup, connect the engine to a driveshaft, strong driveshaft to 15000..etc

  8. #8
    Devil's Cove Junkie G@V1N's Avatar
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    In my humble opinion, it is too much work to put street bike engines in pwcs, because the gain in displacement/horsepower, is nowhere near enough to justify the extent of fabrication/modification required..... That being said, it has been done and will certainly be done again, just seriously consider the amount of work and expense before you begin....

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