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What determines which way to mount trim tabs ( straight or angled )

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Old 12-03-2010, 08:57 PM
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Originally Posted by BenPerfected View Post
That looks like a lot of bow lift for light trim at 55 MPH. Were you porposing at this trim level?
Nope, with a powertech 4 blade 26p it doesnt bounce at any speed.
Its not a light boat either..
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Old 12-03-2010, 09:03 PM
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, I put sleeves on the trim cylinder rods so I could not over tab. Felt like the boat got 3 feet longer.
wouldnt that prevent you from putting them all the way up instead of all the way down?
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Old 12-03-2010, 10:30 PM
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I have tried them both ways on my race boat. Same boat,same power. For what ever reason my Krytonite likes them angled better. It cost me a ton to move them and then put them back. Maybe each boat has its own reasons for why its better on one than another. I can also tell you when I run my tabs at level on my SVL Extreem race boat trimmed out on the edge it makes my boat chine worse. If I raise the tabs out it takes the chine walk out. In my opinion tabs can be your worst or best friend. Use them right for your boat and you will see great progress. Wrong AND YOU MIGHT GET HURT AT SPEED. One of the best set up factorys in the world puts them level (Fountain) Im sure after all the testing they do it works best for them.
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Old 12-03-2010, 10:39 PM
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Nope, with a powertech 4 blade 26p it doesnt bounce at any speed.
Its not a light boat either..
I am pretty sure you are having handling issues because it looks like you have lost water contact with your inter strakes....nothing to hold the boat steady which causes porpoise in a twin or torque "lean" with a single that leads to chine walking. We fixed the handling of our Scarab by lengening the inter strakes to just stay in contact with the water to give the boat stability. The faster you go, the longer the strakes need to be. If there are no stakes in contact with the water, you have nothing but a flat bottom to run on. It is not a big deal to get the strake length right. Look at you picture closely....
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Old 12-03-2010, 11:03 PM
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trim tabs help in 90 % of boat set up over bare stock
what they do is extend the wetted surface of your hull
theres a lot of science to where exactly we place them
i run mine
angled 3 inches in from the chine
3/8 inches above absolute transom bottom acts a bit like a third step
the comments all the way back to the beginning are spot on
i use them as a third step and to keep my hull level
attitude of the hull to the water with my rig is important
fun boat to drive
my set up is average mom and pop performance boats up to the 70mph margin
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Old 12-03-2010, 11:21 PM
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Angled works for me.

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Old 12-04-2010, 08:10 AM
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My strakes all run all the way to the back..

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Originally Posted by BenPerfected View Post
I am pretty sure you are having handling issues because it looks like you have lost water contact with your inter strakes....nothing to hold the boat steady which causes porpoise in a twin or torque "lean" with a single that leads to chine walking. We fixed the handling of our Scarab by lengening the inter strakes to just stay in contact with the water to give the boat stability. The faster you go, the longer the strakes need to be. If there are no stakes in contact with the water, you have nothing but a flat bottom to run on. It is not a big deal to get the strake length right. Look at you picture closely....
Ben
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Old 12-04-2010, 03:03 PM
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wouldnt that prevent you from putting them all the way up instead of all the way down?
You're right. Bad memory (this was 20 years ago). I did it to keep the tabs engaged to prevent the chine walk.
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Old 12-04-2010, 03:42 PM
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I tell everyone in my experience, straight is best as the water just rolls under the trailing edge when angled they act like 2 rudders pushing water in opposite directions. However, you don't get as much bite in the water if you think you need it. Just something I found.

Last edited by bwd; 12-04-2010 at 03:49 PM.
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Old 12-04-2010, 04:26 PM
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Flat. Mine are flat. They create more lift and less drag this way. On an angle they actually spread out making the V wider and deeper, like dragging a sea anchor. This fixes chine walk and other handling problems because it slows you down. To correct these issues and not loose speed mount them flat. They can then use the water all ready moving forward (from the energy from the hull) to stabilize and lift with little loss of energy. Angled tabs also get into green water that is static (IE not moving forward) and this takes more energy drag them through the water, again slowing you down not fixing the problem.
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