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  1. #1
    joeblo's Avatar
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    Hit a wall with my pump

    I need guys running over 85mph to tune in,on my tripple pipe ski i am running the 05 pump set back 2 inch with a vx prop,i seem to have hit a wall with my ski when it hits 85.5-86mph,my ski seems to reach this speed super fast and the pump seems to have reached its limit and cant get over this ,i can tell the ski wants to keep pulling,have tried different props,nozzles but allways seem to change revs but stuck on 85-86,are there guys running over this speed on the 05 pump or have you moved up to a modified skat or have any props for me to try,i am running 7650rpm 7600 @ 85.5-86mph with the 87mm nozzle and 2 inch extension
    Just thinking out load could the pressure relief valves be the problem bleeding to much pressure at top speed
    Last edited by joeblo; 05-05-2008 at 05:30 AM.


  2. #2
    Duke's Avatar
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    Quote Originally Posted by joeblo View Post
    I need guys running over 85mph to tune in,on my tripple pipe ski i am running the 05 pump set back 2 inch with a vx prop,i seem to have hit a wall with my ski when it hits 85.5-86mph,my ski seems to reach this speed super fast and the pump seems to have reached its limit and cant get over this ,i can tell the ski wants to keep pulling,have tried different props,nozzles but allways seem to change revs but stuck on 85-86,are there guys running over this speed on the 05 pump or have you moved up to a modified skat or have any props for me to try,i am running 7650rpm 7600 @ 85.5-86mph with the 87mm nozzle and 2 inch extension
    Just thinking out load could the pressure relief valves be the problem bleeding to much pressure at top speed
    I don't think you are bleeding off to much pressure Joe. The same setup worked on Jerry's conversion at well over 90. Making the boat a little more lose and experimenting with the setup is whats probably going to yeild better speed.

  3. #3
    philip_gpr's Avatar
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    what pitch is the VX?

  4. #4
    DRC 4 LIFE TheDome's Avatar
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    Quote Originally Posted by Duke View Post
    I don't think you are bleeding off to much pressure Joe. The same setup worked on Jerry's conversion at well over 90. Making the boat a little more lose and experimenting with the setup is whats probably going to yeild better speed.

    +1

  5. #5
    sleeplessnMS's Avatar
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    Well your speeds are great but maybe ya have peaked out. Have you tried a 85mm nozzle with say a DF14/24?

  6. #6
    joeblo's Avatar
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    The VX is a 15/22 reving 7600-7650 87mm nozzle 85.5-56mph
    The 14/24 had the trailing edge bent 2 degrees ski reved 7890 85mph 87mmN
    i tried the ski with the vx with a 89mm Nozzle gained 100rpm but 1mph slower
    Also tried the vx with the 85mm nozle revs 7550 lost .7mph

  7. #7
    Hydrotoys's Avatar
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    Play with nozzle sizes.

  8. #8
    Happily Self-Employed WFO's Avatar
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    Quote Originally Posted by joeblo View Post
    The VX is a 15/22 reving 7600-7650 87mm nozzle 85.5-56mph
    The 14/24 had the trailing edge bent 2 degrees ski reved 7890 85mph 87mmN
    i tried the ski with the vx with a 89mm Nozzle gained 100rpm but 1mph slower
    Also tried the vx with the 85mm nozle revs 7550 lost .7mph
    Quote Originally Posted by Hydrotoys View Post
    Play with nozzle sizes.
    Also check the liner to prop clearance on that VX.

  9. #9

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    I'm running nothing special, 14/25 dynafly 7900-8000rpm on an 87mm nozzle= 89mph+ and thats with almost .200 in r&d tabs

    I would try the dynafly 14/24 you have on an 85mm nozzle, that should put your rpms almost dead on and give you about 1mph gain.

    Or try your VX prop pitched a little less so it will turn at least 7750rpm.

    I also think your really close to being maxed out, cause if your running 85mph+ on the seat with fuel than thats awesome for a 1300cc.
    My old 1300 tripple ran 87mph with the tabs jacked down and in superman.

  10. #10
    Autosport's Avatar
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    Richard, I think the housing was sent to Impros to be matched with the VX prop when it was bent, so I think it should be all 100%.

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