23' CC trim tab selection

[FELLOW-SHIP]

Hi Peter B

The ST16 are a very good tab for boats that go faster UP TO 60 MPH. Bennett is really not in the market to build tabs for speed boats 70-100+ MPH. The K-Plane from mercury racing is the tab for that. The ST16 provides more lift because of the 16” back into the water column. Bennett does make custom tab for OEM’s – original equipment manufacturers – meaning boat builders only after prints have been made and engineering departments from the builder and Bennett OK the plans.
If the drop fins don’t work good enough on the 12x12 for you than a longer chord would the best way to go. As for them being to much tab for your boat they would work just fine but as stated 4 actuators take twice as long to go up or down from 7-9 seconds to approx 15 seconds. The only issue that we as Seacraft owners have to deal with is the 12” span because of our longitudinal step hull design.




FellowShip

Just for the Grins

[Water Rat]

Sorry to chime in late on this topic. I have the K-Planes (model 280S) on my 23. I agree with almost everything said so far, and especially FellowShip's comment on the length (vs. width) of the tab. The K-Planes I have are almost exactly the width of the outer "step", but are approx. 18" long. I am no naval architect, but feel the added length improves the ride qualities more because it requires little tab deflection to get the desired results (hence less drag?) and also, I believe, provides more of a "rocker" effect, almost like adding length to the running surface of the hull. I am not too familiar with the dimensions available from Bennett, and would love to hear Tabman's opinion on this. At the other end of the spectrum, I wonder if anyone has any experience with the Volvo "blade"-type system on a 23"?
Good luck

[peterb]

The apparant problem with the Bennett 12 x 16 trim tabs (or so the Bennett rep said to me) is while they are 12" across at the transom, at the back of the tab they taper down to 10" across.

He claimed that I would get better lift from the 12 x 12 tabs.

Don't know if he is right or not.

Peter

[Bmoney1209]

You may want to give these a look. All of the people that I know of who have used them think they are great tabs. I would definately check em out.

http://vppneuapps.volvo.com/ww/QL/ql.asp


FD

[ripndip]

Hello,
After careful consideration and lots of research on several forums, I pulled the trigger on 12x16 Heavy Duty Lencos and installed them this weekend in place of the 12x12 Bennetts. These new tabs have a backing plate that goes up the transom and an adjustable feature where the actuator meets the plane (you can choose different mounting holes depending on the angle of the transom). I also went with the indicator switch from Lenco. I seatrialed the boat in 4-6' seas on Sunday with a full in-floor baitwell, full fuel, oil, and fresh water and THESE are the tabs for my boat. I went conservative on the initial adjustment leaving the trailing edge about 2 1/2" up from the straight edge from the bottom. At 3000 rpm/approx 28-30 mph the tab wasn't even touching the water, so I will adjust them down (just pull the bolt and go to the next hole) to the next notch giving me more usable range. The positives of these tabs versus the 12x12's are I can stay on plane at slower speeds, and the props don't blow out in heavy seas (going slow) coming off the back of one large wave and going up the face of the next.
Bennett makes a quality product, and I don't know of any company in any industry with their level of customer service. My only Bennett option was a 12x16 tab with dual cylinders= more plumbing, more stuff, slower tabs. Also, my Bennett 12x12's were barely 12x12 when measured and had some slight bending as I don't think they were strong enough for this application. The 12x16 Lencos I chose are closer to 17" on the one edge, and are thicker gauge with beefed up channels and a backing plate. They are comparable in price to the 12x16 Bennetts, but have a single actuator. After all my research, and based on how much I use the boat, I think it is inevitable I will end up replacing one or both of these (Lenco) actuators within the next 2-3 years. To me it was worth it for the speed at which they actuate, the bigger size, the appearance (electro-polished stainless with zincs; flush, sealed water proof switch with LEDs) and the no-mess/less stuff in my console.
I have over-tabbed the last three boats I have owned- a 20' Seacraft- 12x12 Bennett, a 28' Bertram 12x42 Bennett, and now this boat with nothing but positive results. That 20' Seacraft would go through anything at 16-17mph with those tabs burning no fuel and not touching the throttles- just stay behind the izonglass! I will try to post pictures soon if I can find the time.

Skyler