Trim Tab Use

[JEBar]

as is pretty much standard practice, to get our boat out of the water and on plane we start with the motor trimmed all the way down .... as the boat speeds up and starts coming out out of the hole the motor is trimmed up until a balance point which keeps it at proper trim .... if/how will that change once we install Bennett?s M80 Sport Tabs with their Auto Tab Control .... should I continue to operate the motor trim manually as before and let the auto control run the trim tabs .... or should I set the motor's trim to its normal on plane position and let the auto trim tab control help bring the boat out of the hole .... having never run a boat with such trim tab control, I'm unsure as to how best use them

Jim

 

[haulnazz15]

Re: Trim Tab Use

With auto trim tabs like those or the smart tabs, trim the way you normally would. You may find that you don't need to trim in as much as before, but likely the best performance will be close to the same settings as before.

 

[JEBar]

Re: Trim Tab Use

thank you, I really appreciate the info

Jim

 

[JEBar]

Re: Trim Tab Use

some disappointing information about adding a kicker motor that I learned today at our local boat dealership has given rise to this question .... when we add the Bennett M80 Sport Tab system to our boat, if I put the trim tabs all of the way down is it possible they will slow down the boat's speed when the main motor is running at idle

Jim

 

[dingbat]

Re: Trim Tab Use

when we add the Bennett M80 Sport Tab system to our boat, if I put the trim tabs all of the way down is it possible they will slow down the boat's speed when the main motor is running at idle Jim

I have never operated a boat that needed the tabs all the way down to get on plane. Maximum lift is generated with an attack angle in the 15-20 degree range. Anymore and the tabs loose their ability to generate lift and start creating drag. With the tabs all the way down you will see a decrease in speed and fuel economy

Note: this 15-20 degrees includes the lift of the boat at take off so rarely do you need to deploy your tabs more than a couple of degrees off plane to get up on plane.

To get up on plane, I drop the tabs maybe 5 degree off plane and trim the motor up to where the prop is going to be parallel to the surface of the water when the bow is in the raised position during the hole shot. I then start making trim adjustments to keep the prop parallel to the surface of the water as the bow comes back down. Once trimmed to cruise speed, I adjust the tabs if need be or typically let Auto Control take over. Once up on plane my best fuel economy comes with the tabs either fully retracted so any tab in the water is going to adversely affect your fuel economy or just barely in the water on the rough days. Auto control does the rest.

 

[JEBar]

Re: Trim Tab Use

I have never operated a boat that needed the tabs all the way down to get on plane. Maximum lift is generated with an attack angle in the 15-20 degree range. Anymore and the tabs loose their ability to generate lift and start creating drag. With the tabs all the way down you will see a decrease in speed and fuel economy

sorry, I didn't make myself clear .... my reason for wanting to install a kicker motor is due to the fact that at idle speed our boat's 90 hp outboard moves the boat too fast for trolling for walleyes .... with the trim tabs, as you note, all the way down it seems logical that they would create drag .... if they create sufficient drag so as to slow the boat's idle speed to a good trolling pace, that could save us thousands by eliminating the need for the kicker .... I don't guess that there is any way we will know for sure until the trim tabs are installed .... your observation that if we have them all the way down that it would be wise to raise them prior to trying to bring the boat out of the hole is well taken

Jim

 

[QC]

Re: Trim Tab Use

Yes, tabs full down will slow your boat speed at idle. I see around .5 MPH drop. I have extra large tabs.

 

[JEBar]

Re: Trim Tab Use

Yes, tabs full down will slow your boat speed at idle. I see around .5 MPH drop. I have extra large tabs.

it just makes sense to me that they would ... it will be very interesting to see how things stack up with our boat

Jim

 

[QC]

Re: Trim Tab Use

Whether or not they solve your trolling speed issue, helm adjustable tabs will be the coolest feature you will ever add to your boat. If understood,and used properly, you will be blown away. I will never own a v-hull boat over say 17 ft. without them.

Oh, and I would skip auto if it is more than a couple of bucks. If you like to control things, and think reasonably technically, you'll want to adjust them yourself.

 

[JEBar]

Re: Trim Tab Use

Whether or not they solve your trolling speed issue, helm adjustable tabs will be the coolest feature you will ever add to your boat.

Oh, and I would skip auto if it is more than a couple of bucks. If you like to control things, and think reasonably technically, you'll want to adjust them yourself.

understood on the coolest feature .... we had factory installed ones on a large Excell which made a huge difference in getting that tub out of the hole .... they had to be worked manually with dash mounted buttons .... the auto control is considerably more than a couple of bucks, so much so that I admit having to do some real thinking about it

Jim

 

[dingbat]

Re: Trim Tab Use

.... the auto control is considerably more than a couple of bucks, so much so that I admit having to do some real thinking about it
Jim

Unless you do a lot of long distance of cruising under varying conditions auto tabs are pretty useless. The only time I use mine is when making long runs in less than ideal conditions or across the tide. I’ll use them to run out to the fishing grounds now and then but that’s only to the keep the boat running in a more or less straight line if I’m walking away from the helm or I have a rookie running the boat.

Sorry I can't help you the speed thing. Putting my tabs down all the way creates lot of bow steer and the boat gets squirrely even at slow speeds

 

[JEBar]

Re: Trim Tab Use

Unless you do a lot of long distance of cruising under varying conditions auto tabs are pretty useless. The only time I use mine is when making long runs in less than ideal conditions or across the tide.

our boat is large enough for 4 adults to comfortably cruise long distances but small enough that when someone moves around in the boat, it really affects the way it sits in the water .... we hope to make several 100+ one way cruises on the Mississippi and Missouri .... during those runs my wife will do some of the driving and lets just say it would be best for her to not try and work any more controls than are absolutely necessary .... hence my motivation for the auto control .... I believe it it would be a much more tension free for her and for me as well

Jim

 

[Georgesalmon]

Re: Trim Tab Use

On the trolling speed question. On my 26' putting the tabs down to troll for walleye had little to no effect. Slowest I could get with main engine was about 3.2mph and the tabs made no difference up or down at that speed. I needed a kicker to get down to the 1.5mph and less I needed. Trolling bags and 5 gal pails did work but no matter where I put them they always got in the way at one time or another. I tried everything even a trolling plate on the motor. That slowed the boat OK but I couldn't steer. Loved the tabs though. Were a wonder running in a cross wind to keep the boat level not to mention getting on plane quicker. Never had an automatic control though, just two switches and very easy to use.

 

[JEBar]

Re: Trim Tab Use

On the trolling speed question. On my 26' putting the tabs down to troll for walleye had little to no effect. Slowest I could get with main engine was about 3.2mph and the tabs made no difference up or down at that speed. I needed a kicker to get down to the 1.5mph and less I needed.

that is exactly what I fear is going to end up being the case with our boat/motor .... but, I have to give them a try .... since adding trim tabs was our #1 priority, it is something we are going to do anyway .... if they do slow the boat down sufficiently, that would be absolutely wonderful .... if not, I'm already collecting estimates to add the kicker motor

Jim

 

[Georgesalmon]

Re: Trim Tab Use

You will never regret adding the tabs. Even if they don't solve you speed problem.

 

[JEBar]

Re: Trim Tab Use

You will never regret adding the tabs. Even if they don't solve you speed problem.

of that we have no doubt .... if they help with the trolling speed, that would be gravy

Jim

 

[JEBar]

Re: Trim Tab Use

I'm getting closer to beginning the process of installing Bennett Trim Tabs on our boat .... our boat's outboard is currently fitted with a "SE Sport? High Performance Hydrofoil" .... it is my understanding that it should be removed and doing so will leave 4 holes in the motor's cavitation plate .... it would seem logical that those holes may need to be filled and if that is the case, what is the best way to do so .... with my luck the answer can't be so simple as to reinstall the bolts/nuts but it sure would be nice if that was the case

Jim

 

[H20Rat]

Re: Trim Tab Use

you could reinstall the bolts, but generally there are no issues with just leaving the holes.

 

[JEBar]

Re: Trim Tab Use

you could reinstall the bolts, but generally there are no issues with just leaving the holes.

thank you .... I'll leave them and see if any sort spray or other issue should develop

Jim

 

[Home Cookin']

Re: Trim Tab Use

If you are still installing a trolling motor I assume you've figured out any conflicts between the tabs and that motor? Can you bow-mount an electric?