Hitting hydrodynamic limit of Alpha One? Maybe Wrong Prop?
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Hitting hydrodynamic limit of Alpha One? Maybe Wrong Prop?

  1. #1
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    Default Hitting hydrodynamic limit of Alpha One? Maybe Wrong Prop?

    Hey guys! New to the forum! I posted this on OSO and figured I get some more feedback here!

    Here's my situation. I have a 22'+ Stingray Maxim powered by a built 383 SBC (AFR 190's, 224/230 HR, 9.4:1) and it seems like I'm hitting a wall at about 67mph+.

    I have ran the boat to 70mph GPS @ 5200 rpm and took a while for those last few mph. I'll get to 67mph fairly quick with the current 14.5" x 23p Stiletto 3 blade that I bought off craigslist haha! I feel like I'm not getting enough bow lift with this prop. Blow's out with a hair more trim above input shaft centerline. I've also been told by Tom @ Hydromotive that I'm at the limits of the stock nose cone of the Alpha. Any truth to this?

    I have also tried a borrowed 21p Rev4 prop which is 14 5/8". Picked up a few hundred rpm, still same top speed, didn't blow out as early, was able to take some more trim.

    Looking for any input from anyone with experience in this type of setup. I Build racecars and this is just a fun hobby but still looking to maximize this setup.

    I feel like I need more bow lift, and a little more rpm. Any ideas?

    Here is a flyby video of my boat.

    https://youtu.be/MxztEWLQf-U



    Thanks!

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  3. #2
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    Quote Originally Posted by Timmy2Stage View Post
    Hey guys! New to the forum! I posted this on OSO and figured I get some more feedback here!

    Here's my situation. I have a 22'+ Stingray Maxim powered by a built 383 SBC (AFR 190's, 224/230 HR, 9.4:1) and it seems like I'm hitting a wall at about 67mph+.

    I have ran the boat to 70mph GPS @ 5200 rpm and took a while for those last few mph. I'll get to 67mph fairly quick with the current 14.5" x 23p Stiletto 3 blade that I bought off craigslist haha! I feel like I'm not getting enough bow lift with this prop. Blow's out with a hair more trim above input shaft centerline. I've also been told by Tom @ Hydromotive that I'm at the limits of the stock nose cone of the Alpha. Any truth to this?

    I have also tried a borrowed 21p Rev4 prop which is 14 5/8". Picked up a few hundred rpm, still same top speed, didn't blow out as early, was able to take some more trim.

    Looking for any input from anyone with experience in this type of setup. I Build racecars and this is just a fun hobby but still looking to maximize this setup.

    I feel like I need more bow lift, and a little more rpm. Any ideas?

    Here is a flyby video of my boat.

    https://youtu.be/MxztEWLQf-U



    Thanks!


    I dont think so, i have a modified lower on my alfa. boat runs 100+ on the bottle 95 off. 406 sbc. large ear, 3 blade.

  4. #3
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    Dec 2013
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    You need more torque and have to take the Hook out of the hull..
    Its kinda factory built in brake for commercial boats.

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  6. #4
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    Try a Turbo 1, it's a bow lifter. I use a 25 pitch and run 5800 on a Alpha SS. Powered with a Dart 406 w/ AFR 195 Elim. Boat is a 18 Donzi.

    Stay away from the 4 blades, stern lifters. Trust me I tried them all.
    Last edited by Tombstone; 07-28-2016 at 03:44 PM.

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