Do smart tabs help for tubing?

[jodyf]

I have a 14 ft with a forty horse Johnson. It struggles to get a tube up on a plane. Just wondering if smart tabs would help for this situation. I know I should get a bigger motor, but finances won't permit that at this time. Just want to have some fun with the kids. If anybody has experience with this, any advice would be appreciated. Thanks

 

[southkogs]

Re: Do smart tabs help for tubing?

Sorry Jody: It's probably more a power to weight issue. A tube doesn't plane in the manner that skis or a kneeboard would. Depending on the load of people, even those will struggle to plane out behind a 40HP. That tube takes a bit to get up on plane, and then takes some speed to keep it on top.

I learned to ski behind a 14' with a 35 HP. It was a buncha' work to get up, and it could get slushy fast (because the boat just couldn't generate enough power). Tube will probably be a little worse than that.

Tabs may help ... but probably not enough.

 

[MRS]

Re: Do smart tabs help for tubing?

Just put tabs on my boat it is 19 ft. 4.3 I know bigger than yours but I do pull a three person tube with three adults on it. The bow never comes down that is with out tabs test ran the boat this weekend with tabs not with the tube but the bow did come down at half the speed and I think this weekend we are to take a bunch of friends out for some tubing so should be way better to get the boat planed out. I would say could not hurt and all in all you will love the way the boat will run and plane out.

 

[metriccrescentwrench]

Re: Do smart tabs help for tubing?

With your setup I'd try putting a fin on the AV plate. It would cost a heck of a lot less than smart tabs and more than likely accomplish what you need. And regardless of what you do you'll want to check your engine height, adjust it so that the AV plat is just above the water when you're running on plane.

 

[JASinIL2006]

Re: Do smart tabs help for tubing?

I think southkogs nailed it. A tube has so much drag that I don't see how tabs (or a whaletail) would make much of a difference. Even behind a much bigger boat, you definitely feel the drag from a loaded tube.

 

[smokeonthewater]

Re: Do smart tabs help for tubing?

personally I think smart tabs WOULD help and I think a prop change would likely help even more

Do you have a tach on that boat?

I wouldn't waste a penny on the whale tail.... at @$50 for it and @130 for the tabs, there's no comparison between the two

 

[NSBCraig]

Re: Do smart tabs help for tubing?

And I think you can still get smart tab blems through iboats for less. Mine are blems and if you crawl under the boat while it's on the trailer you can see the difference.

 

[Jdeagro]

Re: Do smart tabs help for tubing?

Hi Guys;

Let me interject a little here and try to identify the difference between Trim Tabs and a Hydrofoil. A hydrofoil is a fixed trim tab. since it does not angle down the amount of lift is limited at slow speeds. It's wing shape is designed to increase lift as the speed increases. The added planing surface is only the surface which is in excess of the cavitation plate (flange).

The angle of the trim tabs can be adjusted or adjust automatically giving the boat more lift at slow speeds and as they retract the lift is reduced. The surface area of the plates are usually 2 to 2 1/2 times the surface area of the hydrofoil, and they are mounted on each side of the boat to increase stability.

For the best performance upon acceleration you want maximum lift prior to planing which is achieved with trim tabs by the down angle and the plate size. Once on plain it is no longer necessary to have excessive and uncontrolled stern lift as this will drive the bow down resulting in a loss of speed, a listing to the port side, and excessive lean in turns.

Hydrofoils lift the stern at the very center of the boat which is like trying to balance the boat on a teeter totter (side to side) affecting lateral stability.

Trim Tabs provide the boat with overall improvement in balance (front to back and side to side).

The boat hull design dictates the performance characteristics. Flat bottom Boats work well in shallow water and V bottom boats provide more speed. Trim Tabs allow the boat hull to change on demand as they become part of the running surface.

You will more overall improvement from trim tabs than any other single change.

One last note. HP is not the end all for performance. Let's say that you have a 40 HP OB and are considering a change to a 60 HP OB for a gain of 20 HP. If this is to improve the ability to plain quicker ( Hole Shot) then you are likely to spend an extra $1000.00 to get very little. Why? Max HP is achieved at about 5000 RPMs. You are tring to get on plain at about 1/2 the RPMs or 2500 RPMs.

The 40 HP motor will provide 20 HP at 2500 RPMs and the 60 HP motor will provide 30 HP. You are then going to pay $1000. for 10 HP.
Additionally the 60 HP motor is heavier than the 40 and adds more weight to the stern.

The problem with getting on plane is bow angle which is cause by the boat balance. The front end is lighter than the stern so the water pressure upon acceleration raises the front first. Now we are trying to climb a 16 to 17 degree hill. The majority of the HP is wasted on the hill climbing.

What If! Providing extra lift at the back (stern) so that the lift "front to back" is more equal allows the boat to accelerate more level and uses the HP for forward speed. In short let's just get rid of the Hill. Time to plane with trim tabs on a 40HP motor powered boat will be faster than the same boat with a 60 HP motor - noticeably faster.

Changing the prop is like downshifting into second gear. It provides better acceleration but over revs the motor at all speeds. Less top speed and more fuel. The prop should be coordinated so that the WOT RPMs are within factory specs.

 

[smokeonthewater]

Re: Do smart tabs help for tubing?

agree with everything with one exception... changing the prop is VERY effective for towing where more thrust is needed to pull more load up to planing speed and where top speed is not a concern...

I'll add that on looking back my previous statement could easily be taken different than I intended... I meant that adding tabs would help and THEN changing the prop would also be more help AFTER the tabs....

Tabs being for every day use and tabs plus prop for towing duty....


Think tugboats... GOBS of horsepower but propped for 10-15 mph max

 

[Jdeagro]

Re: Do smart tabs help for tubing?

Hi Kevin;

We do not disagree on the prop issue. What I was trying to point out is that dropping down in pitch for the sake of getting on plane easier is not the best solution, especially if it allows the engine to over-rev. Over the years we have seen numerous situation where the boaters have used combinations of both prop changes and trim tabs in order to maximize the performance for their specific need. If the boat is primarily used for towing, the change to a lower pitch in addition to trim tabs will provide major improvements, beyond most expectations.

We have also seen boaters moving up in pitch (with tabs) to improve top speed without sacrificing the ability to get on lane easily.

 

[smokeonthewater]

Re: Do smart tabs help for tubing?

agreed 100%... now make me some free prototype tabs for my cruiser BAWHAHAHA

 

[metriccrescentwrench]

Re: Do smart tabs help for tubing?

Hydrofoils lift the stern at the very center of the boat which is like trying to balance the boat on a teeter totter (side to side) affecting lateral stability.

That statement is laughable, you make it sound like the stern is balancing on a single point and is liable to fall off to one side or another at any instant. As a boat is coming up on plane there is plenty of the boat still in the water on both sides so that "trying to balance the boat on a teeter totter" is simply not an issue. And once on plane a fin will be out of the water, and does nothing except to apply a counteracting force if the boat has a tendency to porpoise.

I've got nothing against smart tabs. I have no experience with them but I think they sound like a good idea. But for a vender to come on here and put down a competing product seems kind of questionable. IMO trim tabs, smart tabs, and fins all have their place.

 

[Jdeagro]

Re: Do smart tabs help for tubing?

Commander;

Thank you for pointing out my communication problem. I do not want to suggest that the balance issue is one that occurs when the boat is accelerating to plane. You are correct when stating that there is plenty of boat in the water at that time. What I am referring to is at cruising speeds and higher. At these speeds the plate provides extra lift to the stern even when it is riding at water level. If the engine is adjusted up high enough (using a jack plate for example) so that the hydrofoil is not touching the water then there is little to no lift, but in the case of I/Os raising the engine is not an option. I use the reference to a "teeter totter" to help create a "visual", and obviously the reaction side to side is not that radical. However, it does not take too much extra lift at cruising speeds to push the bow down a few degrees and cause a torque list to port.

Again thanks for the chance to make myself more clear.

 

[smokeonthewater]

Re: Do smart tabs help for tubing?

I took one off of an I/O that was SCARY when turning fairly sharp at low planing speeds and still leaned way too much at higher speeds... it was a 26' flybridge cruiser and there were a couple times on the test drive that I thought it might actually roll over to the inside of the turn.... took the foil off and it behaved perfectly