Trim Tabs

[albacore11]

I have searched the whole site and also the Bay 190 Forum, but still have not found a good discussion/recommendation on trim tabs on the Bay 190. Lots of trim tab information on the other models, but practically non-existent for the 190,

I am thinking of installing hydraulic trim tabs on my vessel and would appreciate any suggestions/recommendations the rest of you may have.

 

[pamarine]

Albacore:

I can't say that any type of tabs would be negative, While the power of hydraulic tabs is undeniable, the complexity of the systems tend to be overkll for small vessels. You may want to consider Lenco electric tabs instead. I would definitely recommend a controllable tab over the smart tabs, and the only reason I have chosen the Bennett tabs for myself was the NMEA2000 compatibility. If you want info on any tab type or brand, let me know, I have tons of info to lend. Hope this Helps

 

[Whitto]

Pamarine ... why not the smart tabs?

I have been looking at them for my 195DC ... eventually.

 

[pamarine]

Smart tabs

Whitto,

The smart tabs are great if you are looking for an alternative to a hydrofoil (which I try to avoid). However, they do not allow any dynamic control of the vessel while underway, which is a key factor for me concerning maximum safety and comfort. As always, boats are all about compromises, and there is a trade off between cost and performance. My ultimate recommendation is to get the desired performance you want within a cost frame you feel provides value. If you get a cadillac ride but feel you could have retired on what you spent, then the stress will make the decision the wrong one. Hope this Helps.

 

[FloridaBoyFishin]

Please help me to understand... I am a new boat owner and for my first boat i chose the 190 bay(2008). What will the trim tabs do for me? I primarely run in the Gulf of Mexico anywhere from the flats to 20 miles offshore. What would trim tabs do for me and would I notice any difference? I really appreciate any thoughts you can give on this subject!!

 

[Dave LeGear]

Whitto,

The smart tabs are great if you are looking for an alternative to a hydrofoil (which I try to avoid).

If you are talking about those huge plastic ones that looks like somebody chopped off a B52 wing and mounted it on the lower unit I agree. However, the much smaller metal one from BMS

https://bobsmachine.com/product-category/engine-performance-items/true-tracker-stabilizer-plates/

Works well on not only the 190 but 210 hulls in reducing time to plane and minimal plane speeds thus saving on fuel and the ROI on one is pretty high. I also have taken mine off and it made no difference in top end speed. It sure did though in how it got a plane and low speed handling.

No Hydrofoil though will do what trim tabs will and that is not their design intent. Now I see a place for tabs on a boat "if" you feel you need them, but I have seen the need on my 190 for them and mine runs pretty flat. I though play special attention to how my boat is loaded / blanced so my hull runs well. Here again, my 190 and engine combo is far from a stock unit

 

[pamarine]

Please help me to understand... I am a new boat owner and for my first boat i chose the 190 bay(2008). What will the trim tabs do for me? I primarely run in the Gulf of Mexico anywhere from the flats to 20 miles offshore. What would trim tabs do for me and would I notice any difference? I really appreciate any thoughts you can give on this subject!!

Tabs will help you acheive lower planing speeds, better control and handling capability, and a lower bow angle when running, increasing visibility. Hydrofoil plates also accomplish this, but the main drawback is plates increase the lift force on the engine, and thus increase the shear forces on the engine mounting bolts, whereas trim tabs increase the lifting force on the transom itself, which is generally better for the hull. Also, as stated earlier, traditional tabs allow the operator to dynamicaly adjust for chagning boat loading conditions and seas, whereas plates and SmartTabs are statically set for one condition. Hope this Helps!

 

[j-place]

this link may help

BoatUS BoatTECH Guides: Trim Tabs

 

[Dave LeGear]

Hydrofoil plates also accomplish this, but the main drawback is plates increase the lift force on the engine, and thus increase the shear forces on the engine mounting bolts

That statement is a stretching it a little don't you think? Unless one is getting some very, very, low grade bolts from Communist China or re-using bolts again after their first install (bolt stretch) I have never seen any Hydrofoil create these extra high lift loads that quality engine mounting bolts could not handle.

Matter of fact, most engine bolts far exceed the stress requirements and clamping force needed for the job. The transom material is going to break away before the bolts will if they are snug and at the proper torque. If needed here is a chart so you can go check yours and see if your dealer used bolts that are up to the task

Bolt Depot - Bolt Grade Markings and Strength Chart

Flip side of the coin though, if one wants to look at attentional stress on the stern... The Hydrofoil by getting the stern to come up faster at lower speeds, can also reduce the twisting loads on the stern by getting more of the engine out of water faster thus reducing lower gear case drag. In essence much like using a shorter screw driver to "try" and pry open a paint can lid This is why you can run a lower plane speeds after installing a quality hydrofoil. The one constant in all of this is one cannot get lift (Hydrofoil or Trim Tabs) without additional drag "unless" you have a way to raise either of these devices out of the water when running

 

[pamarine]

Stresses

Dave,

One thing to point out is, as you stated, engine bolts are designed for tensile loading, not shear loading, and hydrofoils increase the shear loads on the bolts. I do not mean to imply that the additional stress would lead to premature failure of the engine bolts. In fact, I don't think there has ever been a case outside of a lab where a hydrofoil has been the sole or main factor in engine bolts failing.

That being said, I have seen several instances where the transom around the bolts has failed after being weakened due to some other factor, including rotting or poor engineering. In cases of transom failure, there is some anecdotal evidence to suggest that engine-mounted hydrofoils aggrevate such failures. I do not think this is a concern on the Triumph boats, if is my firm belief that the materials, engineering, and manufacture provide more than enough safety margin to allow for the safe use of a hydrofoil stabilizer.

The main point I was trying to make was, the purpose of trim tabs and hydrofoils is to lift the transom, and the most efficient way to do this is through lift devices mounted directly to the transom, not through devices mounted to the engine and transfering the lift through through the engine mount. Hydrofoils do add stresses to components that were not originally designed into them. Will those added stresses cause failure? Outside of extreme cases, probably not. But I am of the opinion that when trying to solve a problem, go for the most direct, simplest solution.

With the release of the SmartTabs by nauticus, I really see no need for the traditional hydrofoil stabilzer. They were intended as an economic alternative to traditional trim tabs for smaller boats, and the smart tabs now fill this role. When recommending lift/stabilzing devices, the question I ask my customers now is whether they want to control the tab positions while underway or not, and use that answer to decide smart tabs or tradtional tabs. Hope This Helps!