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  1. #1
    ou812's Avatar
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    RPM increase with 3" riva intake

    As quoted from the riva site:

    "Power Filter provides greatly improved acceleration and a 150~200rpm increase by replacing restrictive stock intake system."

    I have this intake & saw only a 20 rpm (8180) increase & I ran it on the same day 2 hrs after my 8160 rpm run with stock prop, 2.0 wedge & flat B/O's.

    Am I bumping the rev limiter or something? It sounds a little different I guess. But honestly, I don't really feel much increase in the powerband.

    Has anyone really seen that much rpm increase? I kinda feel like it's money spent & that's it.

    Am I missing something? It's installed so it's staying till something better "proven" comes along.


  2. #2
    Gotta love this sport! 05Limited's Avatar
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    You are most likely on the limiter. If you add 1-2mm of pitch to the impeller you should pick up 1-2 mph and still be able to turn 8160-8180 rpm.

    Jeff

  3. #3
    ou812's Avatar
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    I hope so. So what IS the 06 rxp limit set at? On the trailer I've seen 8300-8400 rpm but feeling the limiter kick in with a quick blip of the throttle when blowing it out.

  4. #4
    Gotta love this sport! 05Limited's Avatar
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    8200... The '04-'05 skis would usuallly run at 7950 stock and gain around 200 rpm with the Riva air intake. The '06 skis tend to run around 8100 stock, so there isn't much room for improvement without hitting the limiter. Also, the '06 skis read in increments of "20" rather than the earlier skis that read in incremnts of "50". You will most likely never see 8200 (unless you come unhooked) because the limiter starts retarding the timing.

    I've got an altered stock prop you can try if you like.

    Jeff

  5. #5
    shhr's Avatar
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    Jeff can help you alot he has just a few parts

    one more thing DO NOT rev your ski that high out of the water

  6. #6
    Quote Originally Posted by ou812 View Post
    I have this intake & saw only a 20 rpm (8180) increase & I ran it on the same day 2 hrs after my 8160 rpm run with stock prop, 2.0 wedge & flat B/O's.

    Am I bumping the rev limiter or something? It sounds a little different I guess. But honestly, I don't really feel much increase in the powerband.

    Has anyone really seen that much rpm increase? I kinda feel like it's money spent & that's it.

    Am I missing something? It's installed so it's staying till something better "proven" comes along.
    YES! Finally someone that ran into the EXACT problem I had last year...except I went from 8100RPM down to 8050 RPM on my '04 RXP with stock prop still, but I gained 1mph somehow. Confused the hell out of me. Once I added the wedge and 14/19 impeller though I gained another 2 ~2.5mph and my RPM went back to 8100. I can't explain it. I took Jerry's advice and threw on the 14/19 without worrying about it anymore and it all worked out. So all I can say is to put on the other prop and give it a whirl!

  7. #7
    EZ Dock of Long Island Shibby1485's Avatar
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    Quote Originally Posted by ou812 View Post
    On the trailer I've seen 8300-8400 rpm
    dude, be a little more gentle with that thing on the trailer.. you can run it and rev it, but to be pulling it and smackin the rev limiter on the trailer .... be gentle

    and add more pitch to your prop... you running stock prop? if so, get rid of it

  8. #8
    ou812's Avatar
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    Quote Originally Posted by Shibby1485 View Post
    dude, be a little more gentle with that thing on the trailer.. you can run it and rev it, but to be pulling it and smackin the rev limiter on the trailer .... be gentle

    and add more pitch to your prop... you running stock prop? if so, get rid of it
    Haha, I've been riding since '89 so I'm not too lame as to hold the revving up that high. I'm used to the 2 strokes that rev out so I hit it good once. I only did it once & when I noticed the rev limiter kicking in I knew that was too much. At senators wash I was seeing 8180 solid at just below sea level.

    Oh yeah...I've tried other props already.

    The lake is 1250ft above where I ran these #'s

    stock prop = 8160 @ 69.6 full tank & 70.2 1 bar above 1/2. spun 7460rpm out of the hole

    3 blade 13/18 = 8000 @ 68.2 full tank. Spun 7500rpm out of the hole

    14/18.5 concord = 8120-40 @ 69.2 full tank..this prop spun 8020 out of the hole.

    The props have been repitched by impros already except the stock one.

    14/18.5 is now 14.5/19
    13/18 is now 13/17.5

    So i'll run 'em again!

    Oh, after the 10.5 hr oil change the ski gained 80-100 rpm. from 8040-60 to 8160 at senators with stock air intake.

    here's the thread on the mod comparrisons. scroll to post #31
    http://www.greenhulk.net/forums/showthread.php?t=15585
    Last edited by ou812; 12-18-2006 at 12:01 AM.

  9. #9
    Moderator Insanediego Joe's Avatar
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    Its those crappy block offs your running! You need some good quality slightly used high in demand re block offs my friend!

  10. #10
    ou812's Avatar
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    Quote Originally Posted by Insanediego-RXP View Post
    Its those crappy block offs your running! You need some good quality slightly used high in demand re block offs my friend!
    But someone has to pry them off their unused hull!

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