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  1. #1
    MPower's Avatar
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    RXPX260 15 PSI and 76 mph?

    Guys, looking for some tuning tips for this S3 hull.

    2012 RXPX
    85-90 deg and 100% humidity 200 foot elevation

    15.2 PSI @ 8600 RPM
    76 mph on GPS
    AFR 12.1 at WOT

    Rev limiter set at 8750

    Solas 14/18 pitched by R&D
    R&D intake grate
    R&D trim tabs
    83mm nozzle and stock cone
    R&D sponsons


    Where can I find speed in the setup? Obvious things are go down on the leading edge of the prop, 85/87mm, nozzle, lose the trim tabs?. Otherwise I am kinda at a loss bc the motor runs strong. I need to adjust the steering because you have to turn left to go straight, but otherwise everything is smooth and flush under the hull.


  2. #2
    boost junkie skidoochris's Avatar
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    sounds like your there, that's a heavy ski
    cooler temps or more boost/rpm will get you some more speed

  3. #3
    Boost addict hotbird's Avatar
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    a px is a T3 hull not S3

    I dont think your to far off on speed considering the heat and humidity.

    You upgrade or test the intercooler?

    This hull is not the best for top speed numbers.

    The turning thing maybe the r&d grate not sitting straight or engine alignment.

  4. #4
    JFizzleJR's Avatar
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    I'm curious about one thing you mentioned. Can you explain how engine alignment would affect steering alignment?

    Quote Originally Posted by hotbird View Post
    a px is a T3 hull not S3

    I dont think your to far off on speed considering the heat and humidity.

    You upgrade or test the intercooler?

    This hull is not the best for top speed numbers.

    The turning thing maybe the r&d grate not sitting straight or engine alignment.

  5. #5
    Boost addict hotbird's Avatar
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    I have heard if the engine alignment is off it can pull to one side. I guess only if the pump shoe is off.

  6. #6
    Mod less, ride more! troyheb's Avatar
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    Trim tabs & ride plate angle. Some skis seem to come with some down angle on the plate.
    I have Riva tabs. I played around with them and seem to have found a happy place with them, but they definitely are not plug and play. IMO, the stock tabs are the fastest.
    The trick with this hull is to try and get it as far out of the water as possible, without it wanting to bounce.
    Also not sure about that R&D grate being best for speed.

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  8. #7
    MPower's Avatar
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    Quote Originally Posted by hotbird View Post
    a px is a T3 hull not S3

    I dont think your to far off on speed considering the heat and humidity.

    You upgrade or test the intercooler?

    This hull is not the best for top speed numbers.

    The turning thing maybe the r&d grate not sitting straight or engine alignment.
    Im running the r&d intercooler with cooling kit

    what nozzles are guys running on these things? I've got the adjustable tail cone too but not going to bother using it with the stock 83 nozzle.

    r&d claims 81.5 @ 8750 rpm, that seems like a stretch...

  9. #8
    Rt-HemiBoY's Avatar
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    Forget r&d you wont make that speed with 15lbs of boost....your speed and the mods sounds good.. and thats probably the most you gonna get there.. this hull are real hard to get mph out of the....

  10. #9
    Boost addict hotbird's Avatar
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    Quote Originally Posted by MPower View Post
    Quote Originally Posted by hotbird View Post
    a px is a T3 hull not S3

    I dont think your to far off on speed considering the heat and humidity.

    You upgrade or test the intercooler?

    This hull is not the best for top speed numbers.

    The turning thing maybe the r&d grate not sitting straight or engine alignment.
    Im running the r&d intercooler with cooling kit

    what nozzles are guys running on these things? I've got the adjustable tail cone too but not going to bother using it with the stock 83 nozzle.

    r&d claims 81.5 @ 8750 rpm, that seems like a stretch...
    for top speed I run 83mm for fun I run 86mm

    the bigger nozzle slowed me down 3-4 mph.

    Also I have a r&d grate.

  11. #10

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    Through the last few years of this hull being available its become quite apparent that 72-75MPH is easy to get and you fight for every mile per hour after that. Hull sits heavy in the water and its hard to get out of the water.

    OP it really sounds like heat might be holding you back a .5-1 MPH and 100RPM or so. Beyond that I'd say more RPM and boost is what your going to need.

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