Trim tab question...top end loss????
 

I purchased my 2102 VIP Victory early this spring without tabs. I followed the directions carefully, I thought, when I put them on. I did it by myself, so it was a little difficult. My question is; when I did my final measurement of the lift of the trailing edge of the tab, it was only about 1/2" up from the straight edge. The direction said I think about 1" is where they should be. Is it possible that this could be causing excess drag for top end speed? It seems that I lost about 1-2MPH on top after I installed the tabs. The leading edge of the tabs are about1/8th to 1/4"above the trailing edge of the boat as it was told in the directions. I may end up redrilling the holes in the tabs and relocating the cylinder so that I can adjust them up farther out of the water. What do you think???????? Thanks. Justin. BTW the tabs are 12"x12" single cylinder.

does anyone have any suggestions?? thanks J.

I added Bennett tabs to my Liberator and had mine about an inch up from the straight edge. If I remember correctly 1/4 to 3/8 up from the bottom. I saw no difference in speed with the tabs all the way up.
My bet is your still dragging them in the water , because they really shouldn't negitively impact your speed when retracted:(

You are likely dragging them slightly. Anytime you add something to the surface of the boat you can lose speed. If there is a way to do it safely you need to have someone look at them while you are on plane. If they are pushing down on the water then you will scrub speed. But there may be no way to raise them high enough to keep them out of the water-that depends on hull form, x-dimension, and speed.

"Never Argue With An Idiot. He'll Drag You Down To His Level And Then Beat You With Experience. "
That is hillariously true!!!

Thanks for the suggestions. I don't think that I will be able to see them because of the swim platform. But I am almost sure that they are dragging a little. I think that if I reposition the cylinder mount on the tab, I will have plenty of throw yet. I never fully extend the cylinder, even with a full load in the rear and noone in the front, on take off.
Any other suggestions would be appreciated as well .
Thanks guys. J.

Are these Bennett tabs with or without trimdicators? If so then there is another possibility for adjustment without remounting the cylinders.

They don't have trim indicators, but the cylinders are bottomed out when the tabs are all the way up. Don't really see any other way, but I could be wrong????!?

Before you try remounting them, Disconnect the tab from the cyl. and duct tape the tab up higher to test what effect mounting the ram higher will have. Most likely your speed loss is not from the tabs. 1 -2 mph could be gained or lost from the air temp, water conditions, weight in boat etc..

This is why I ask you guys these things. Awesome idea! I have received nothing but great advice on this sight ever since I joined a month ago. I wish I would have years ago!!!! Thanks again everyone.

Pray for May!!! Hell, even April will do in Iowa....

Justin

Wish I had more advice to offer!

36,000,001 use for good ole DUCT TAPE!

Since these are Bennetts without the trimdicators you can trim the plastic stop down inside the cylinder. Bennett actually sells a different top portion with a modified stop length but without the trimdicator wires you should be able to do it yourself. This will give you the additional retraction you want.

If I decide that the tabs are causing too much drag, I will go ahead and try trimming them down. I will have to look at the cylinders closer to see how hard this would be. I'm not very familiar with this type of mod. If it was a sled, it would be a diff. story, but I haven't done a whole lot of boat mods yet.........key word 'yet'. I'm learning, thanks to you guys! What steps do I need to do to trim this down? J.

Before you go drilling any more holes, call Bennet. I believe that tey make an offset mount to go on the transom.

My cylinder comes down from below the swim platform on my boat. The top of the cylinder isn't attached to the transom. The top comes from farther back and then angles down and forward to the tab. Hard to explain, but if I were to add an offset mount, that would shorten the distance between the top mount and the tab mount, therefore pushing the tab downward. Thanks for the reply though. J>

Justin. it is easy to trim the stops on the bennetts. i did it this year.

I have a 272 formula that has the silent thunder swim platform (BIG) and required the special shortie bennet rams. i blew one cylinder out this year and replaced with a typical cyliner, not knowing the formula had special shorties. for 1/2 the year it seamed the boat listed slightly. and i lost 1 mph on gps.
I wondered if i had water in the hull, wife gained alot of weight???? engines getting tired.......not sure

anyway i called bennett after looking closely at the tabs and realizing the new one was longer by 1 inch. they said they make a shorter one but in 3 minutes i could fix mine.

here is the process:

step on the tab extending it down . take a large vicegrip with a cloth and clamp the shaft right at the botom of the cylinder so that it stays extended. (there is a spring inside that wants to pull it up)

then unbolt the bottom attachment to the tab. push the tab down out of the way and then simply unscrew the cylinder from the top mount. turnning counter clockwise. place a bag or somthing under this spot so not to drip some hyd fluid on the floor etc. but not much drips out.

set the cyliner out of the way somewhere upright (there is some volume of fluid in it).

you will see the stop on the top attachment. it is a piece of plastic literally glued inside the treaded area that stops the plunger in the cylinder you just removed. carefully cut what you want off with a hack saw( i cut exactly 1 inch) clean all shavings so as not to get into the fluid after reinstalling. and re thread on your cylinder.
attach bottom to tab. Step on the tab, and release the vicegrip.

cycle the tabs full down and up a couple times and this automatically purges the air out of the system

done

BUT.. check for sure first by tieing up your tabs and seing if you get your speed back.

you could also have martiniboat make you a set of tabs(bennet replacement) his already has a offset to raise them higher Im sure he could add more, plus they work alot better then the bennet tabs and look better

When you trim them all the way up do they stay level with the bottom of the boat or do they lift to a higher attitude. If they do not lift up a bit past level with the boats bottom then you are going to loose a bit of speed. I run my boat with them up almost all the time. When it is rough I find that I run them level or just a touch down. This is with K-planes but the idea is the same. Sounds like your are not getting them to lift up high enough.

Jon

my old standart Bennett taps singel ram !!

now my new plate for my old rest !!!

what kind of speedo are you running? GPS or conventional. if conventional make sure it is clear of debris.