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  1. #1
    philip_gpr's Avatar
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    EFI air box set-up - free mod - easy mph gain

    In case you missed it, buried in the Kerry TB test thread is his description how he sets up the air box on his EFI ski.

    For those of you that ride on flat water and the inside of your hull ALWAYS stays dry here is some free mph for you. I would also add, if you can I would leave the wire screen in place.

    "The stock bodies were set up with the top of the stock box removed and the wire screen removed so the bottom half with the stock vilocety stack remained in place."


  2. #2
    2000 GPRXP 4tec shooter98xpl's Avatar
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    Phillip, I just finish testing that theory out. That information has actually been out for a while, in fact, Leo had told me this a while back.
    I went out today with no air box on and just the small rubber boots on the throttle bodies. I saw no gains compared to the black air box with the screens removed. Either my boat is already getting enough power or my shit is fucked up, I think its the first.
    Just food for thought.
    SHOOTER

  3. #3
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    Quote Originally Posted by philip_gpr View Post
    In case you missed it, buried in the Kerry TB test thread is his description how he sets up the air box on his EFI ski.

    For those of you that ride on flat water and the inside of your hull ALWAYS stays dry here is some free mph for you. I would also add, if you can I would leave the wire screen in place.

    "The stock bodies were set up with the top of the stock box removed and the wire screen removed so the bottom half with the stock vilocety stack remained in place."
    Just to be clear I have no testing other than the front snorkel removed to disconnect the first air box. Dont even know if that helps just always done it.
    I have done only one other test and thats the riva filter on the front of the air box seemed like it gained 10 to 20. I have never tested the velocity stack against anything except the only time I have run that was on the ross test and thats how I do all of them now.

  4. #4
    2000 GPRXP 4tec shooter98xpl's Avatar
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    So what your saying is you've never run your gpr without the airbox on it? Airbox minus screens? airbox with the screens?
    I did notice at the beginning when I took the screens out, I gained a little more acceleration and midrange, a few rpms on top. I tested today and I saw no difference in rpms at all, none zilch nada.
    SHOOTER

  5. #5
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    Quote Originally Posted by shooter98xpl View Post
    So what your saying is you've never run your gpr without the airbox on it? Airbox minus screens? airbox with the screens?
    I did notice at the beginning when I took the screens out, I gained a little more acceleration and midrange, a few rpms on top. I tested today and I saw no difference in rpms at all, none zilch nada.
    SHOOTER
    correct

  6. #6
    GPHOTROD's Avatar
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    Cool Hmmmm Never tested

    Read 2nd to last paragragh


    QUOTE=Rocketman;354388]Aform member sent me a set to try right before mudbug. I put them on Amys 1300 . The visual examine showed same size on top. The bottom has a break or ring that graduly opens up to the bottom. All I could see was that this was smoothed out and blended. No size incress was noted that I could see or measure. The plate screws were cut off some but there not out much anyway. Boat was taken to the water and tuned. 2nd day prop was adjuste and retune and the set point was the same at about 5 on the top speed.This was with the Rossnemo throttle bodies.
    Rpm was 7260 max and was very consistent.


    On the trailor and changed to the stock setup with the stock velociety stacks. nothing else was changed all settings stayed the same.
    Back in the water the rpms were now 40 lower or 7220.
    I tried to richen and it got worse starded to lean and the rpms begin to come up. At 2 on the high speed the rpms were 7290 back to back pass after pass and that was the peack. So a 30 rpm loss was noted with poorer fuel consumption using the ross vs the stock set up.Acerlation midrange was unchanged.

    I did not want to say untill I had unbiased confermation from others.
    The person that loaned them to me noted no improvment at all in top rpm and acerlation was the same.
    There is one more person that also lost 30 rpm. So my finding were confirmed by sinetific testing so my findings are valdated as far as I am concerned.
    If they showed me an improvment I would happyly recmond them for any one including my customers.

    I make no money either way with this. No dog in that hunt, I get the shit anyway so might as well tell the truth. I am a tester thats what I do thats how you go fast elmite the things that slow you down and keep the things that make you faster.

    This is what I found your results may very and I am happy for you.
    The stock bodies were set up with the top of the stock box removed and the wire screen removed so the bottom half with the stock vilocety stack remained in place. There may even be a better way I doint know that was the only way they were tested that day.

    If I had seen even a 40 rpm gain we would have kept them on for the bug and had that option to purches them to keep and replace them to that person later.
    Just what I found[/QUOTE]
    Last edited by GPHOTROD; 07-29-2007 at 08:04 PM.

  7. #7
    One day at a time..... N8R's Avatar
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    yes..... no.....yes.....no

  8. #8
    Chrisrokc's Avatar
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    I have been running mine with open throttle bodies for awhile. Not sure if there are gains but it runs good. I was running a Riva Race Flame Arrestor thing before.

  9. #9
    philip_gpr's Avatar
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    "I went out today with no air box on and just the small rubber boots on the throttle bodies. I saw no gains compared to the black air box with the screens removed."

    hmmmmmmm, not what I expected

  10. #10
    One day at a time..... N8R's Avatar
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    Quote Originally Posted by philip_gpr View Post
    "I went out today with no air box on and just the small rubber boots on the throttle bodies. I saw no gains compared to the black air box with the screens removed."

    hmmmmmmm, not what I expected
    thanks for sharring. i saw about 30 rpms but, temps also dropped in the 2 hrs.(storm was comming)

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