Smart Tabs on Deck Boat

[NEboater28]

I recently installed smart tabs in my hurricane 187 I/O. I read tons of reviews and expected some improved performance. I got the 60lb actuator per the recommendation of the nauticus rep. I did a test run over the weekend. I lost about 4mph off my top end. My hole shot was not noticeably quicker. The only benefit was maintaining about 3 mph slower on plane compared to before than before. Are these the expected results? Anyone have experience with these on an I/O deck boat setup? I already have a 4 blade prop on the boat (which has been an ongoing saga to find the right one). I know my hurricane is a heavy boat (3500+ lbs) so I'm not sure if I should have a larger actuator or need to make adjustments to help the hole shot and bring back my top end?? Any thoughts?

 

[Maclin]

Re: Smart Tabs on Deck Boat

Did you talk to Nauticus about this? I think their techs would say with SmartTabs, if you lose top end then the actuator is too stiff or not in the least leveraged hole. Talk to them, about that actuators you have, what hole is used now, and what other tuning you may have done after you installed their tabs.

 

[doyall]

Re: Smart Tabs on Deck Boat

My Azure 22' sportdeck has Lenco 9x12 tabs. Dry weight is listed at 4,400# so with several people, half a tank of gas, half a tank of water and gear it is well over 5,000#. It is pushed by Duo Prop (factory recommended F5 prop set - 21.75 pitch +/-) 5.0GXi Volvo Penta rated at 270 HP. I can definitely tell a difference getting on plane with a full load when using the tabs and staying on plane at slower speeds. (When using a Quicksilver Thunderbolt 22.5 pitch prop set getting on plane is noticeably more difficult even with tabs engaged.) As I have never run the boat without the tabs I can make no comparison to top speed but I would suggest at WOT there would be no need for tabs to be engaged to any degree. I surmise this is what Maclin refers to as being in the 'least leveraged hole'. If tabs were engaged I could imagine a noticeable loss of top end. Best I can tell when properly installed tabs should extend past the transom on the same plane as the bottom of the hull. If the tabs do deflect downward any I would suggest they are not properly installed or adjusted. I do not think one can reasonably expect trim tabs to provide any additional speed at WOT or turn a sofa boat into a drag racer. Tabs should help to get on plane quicker but it is still not going to be a blazing fast, head snapping take off under any circumstances.

 

[NEboater28]

Re: Smart Tabs on Deck Boat

Ok maybe I'll reach out to Nauticus in the AM. I got the pro-troller bracket so I can flip them up or engage them depending what I want. I have it at the middle hole which was recommended during the installation. I guess my fear with going higher up (more level with the hull) is that I'll lose my slower planing speed. They advertise better hole shot, better top end, and lower planing speed. I guess I want my cake and eat it too. I like the lower planing, I can live with the hole shot that's about the same, but I don't know if I'm ok loosing so much of the top. I lost about 4 mph going from a 3 blade to a 4 blade prop, and now another 4 mph, is a pretty significant hit from the stock 3blade aluminum...

 

[dan02gt]

Re: Smart Tabs on Deck Boat

Changing the hole they mount in shouldn't hurt your planing as there is not enough water pressure at those slow speeds to make them start retracting. The holes are also done in a arc as to not change the position of the tab when it is fully down no matter what hole the actuator is in. I would move it one hole and test it out and go from there.

 

[doyall]

Re: Smart Tabs on Deck Boat

After reading this on Nauticus' web site:

"Principle of Operation: Smart Tabs utilize a Nitrogen Gas filled Actuator to hold the trim plates down during low speed operation, and allow the water to ?automatically? push the plates up (horizontal) at higher speeds. This provides additional ?lift? to the stern at slow speeds creating a more level attitude.
ADVANTAGES
Reduced Bow Rise: In addition to a more level ride at slower speeds, the minimum planing speed is significantly reduced. The result is that you will be able to run at the intermediate (comfortable) range which is not available without tabs. This may be especially important when in rough sea conditions.
Faster Hole Shot & Acceleration: The additional ?lift? not only reduces the ?on plane? speed, but it allows the prop to efficiently attack the water, using all of the energy to propel the boat forward. Trimming the engine (which uses the prop energy to correct the boat attitude) can be minimized resulting in more forward thrust."

I would suggest that use of the force of moving water during boat operation to 'raise' the tabs at higher speeds is the functional equivalent to having non-automatic tabs engaged downward during the entire boat operation. No wonder top speed is reduced. Looks like you need a retractor kit. Cha-ching. BTW, I never did see where they advertised better top end. I would think they know better. And I can't help but believe that the only reason there would be any faster acceleration is if you come up on plane quicker, which you infer didn't happen. I suspect the boat is underpowered in which case there isn't much you can do to get better overall performance.

 

[NEboater28]

Re: Smart Tabs on Deck Boat

From nauticus website (mentioning top end)

"There is no doubt that SMART TABS solve problems, but this simple fully automatic trim and stabilizer system offers improvements for small craft well beyond the consumers desires and expectations. Improvements in acceleration, bow angle (?hole Shot?), ride and handling, top speed, and even fuel economy are documented by OEM builders, by numerous national and international magazine tests, and most important, hundreds of consumer testimonials. Over the years and after selling thousands of sets to satisfied customers our confidence has grown to the point that we assure customer satisfaction with a ?money back performance guarantee."

I have a 19 foot boat with a 220hp mpi engine... I don't think it's underpowered. I got 50 mph with the stock 3 blade aluminum prop, but everything I've done since then, a couple 4 blade props and now the tabs have brought me to 42 mph. Pretty significant. I expected to loose some top end, just not that much. I'll play around with the tab positions this weekend and hopefully I can find a happy medium.

 

[doyall]

Re: Smart Tabs on Deck Boat

From nauticus website (mentioning top end)
...
I have a 19 foot boat with a 220hp mpi engine... I don't think it's underpowered. ...

What can be found by reading! They even appear to specifically 'guarantee' a 2 to 4 MPH increase on page 10 of this document http://www.nauticusinc.com/pdf/nauticus_smart_tabs_tech_info.pdf . How bold. Hope it is not too late to invoke that 'guarantee'. (I did notice there was no such claim contained in their general warranty statement.)

As it relates to being underpowered, any boat that does not have an engine with the maximum rated horsepower is, in my opinion, underpowered. Your and my boat included. It appears as though you have reached the point of diminishing returns with your current setup. You simply need more horsepower and torque because your goals are mutually exclusive without it.

Let us know how it turns out.

 

[Grandad]

Re: Smart Tabs on Deck Boat

I can see certain circumstances where adding Smart tabs would increase your top end. I have not yet fully experimented and adjusted mine that I installed last fall, but what I have realized is that I can now trim my I/O outdrive up/out without raising the bow. Before tabs, I always ran with the drive full down/in to give me the best top end. I know full down puts the cavitation plate on a different plane than the keel, which must be inefficient. So, I'm hoping that now with the tabs installed, I'll be able to have the prop shaft running parallel to the keel. I think that whether the tabs help raise your top end depends on just how out of whack your drive's alignment is before you add tabs. Either way, it's kind of a risky statement by Nauticus. - Grandad

 

[JASinIL2006]

Re: Smart Tabs on Deck Boat

I am not sure if this is what Nauticus means, but on my boat, the practical top end speed at which I can boat was increased because I no longer have any chine walking. Before my Smart Tabs, I couldn't fully open it up because the boat would start chine walking, which is not fun at all. Now, I'm very stable at the top end, so I actually can go faster.

 

[doyall]

Re: Smart Tabs on Deck Boat

... I think that whether the tabs help raise your top end depends on just how out of whack your drive's alignment is before you add tabs. ...

Excellent point.

 

[NEboater28]

Re: Smart Tabs on Deck Boat

I got a prompt response from the nauticus rep. He suggested I move the position of the tab to the highest setting (least angled into the water), so there's less drag. I guess this may be effecting both my speed and hole-shot... Makes sense.

He also suggested I remove the 4 blade prop I have and put back the stock 3 blade prop for maximum benefits from the tabs. It seems counterintuitive, but he's the expert. I'm not really sure how that would work. I guess my top end would bump back up, but I don't want to loose the hole shot. I guess I'll give it a try.

 

[BeachRum1962]

Re: Smart Tabs on Deck Boat

I got a prompt response from the nauticus rep. He suggested I move the position of the tab to the highest setting (least angled into the water), so there's less drag. I guess this may be effecting both my speed and hole-shot... Makes sense.

I think you are misinterpreting their instructions. When you make adjustments to the tabs you are not changing the angle but instead you are changing the force required to push the tabs. You are either increasing or decreasing pressure but the angle stays the same.

 

[NEboater28]

Ok, so when he said the highest setting, I assumed me meant that I needed to change the hole that the pneumatic actuator goes into. There are 5 holes, so I was just going to move the hole where it connects to the tab. That would change the angle. Am I incorrect? Or is there a way change the pressure in the actuator itself?

 

[BeachRum1962]

Ok, so when he said the highest setting, I assumed me meant that I needed to change the hole that the pneumatic actuator goes into. There are 5 holes, so I was just going to move the hole where it connects to the tab. That would change the angle. Am I incorrect? Or is there a way change the pressure in the actuator itself?

When you change the setting you are NOT changing the angle of the tab (tab position stays constant), what you are changing is the angle of the actuator and hence the pressure applied to the tab. if you want to decrease pressure (i.e., decrease the force of the drag on the water, then change the setting to the hole closest to the boat (I can't remember if that is 1 or 5). See page 9 of the document linked here http://www.nauticusinc.com/pdf/6_08_manual.pdf

 

[smokeonthewater]

Eh details aren't important... Change it... If it gets better keep going... If it gets worse go the other way... Don't over think a simple process..... Yep try the 3 blade prop... Same theory... If it's better go w it.

 

[BrianVT]

I guess the Smart Tabs didn't end up being as effective on a deck boat as they are on some other boat types? I was tempted to try them for help planing with a heavier load.
Would like to hear from the OP. (I realize this is an old thread.)

 

[JASinIL2006]

I guess the Smart Tabs didn't end up being as effective on a deck boat as they are on some other boat types? I was tempted to try them for help planing with a heavier load.
Would like to hear from the OP. (I realize this is an old thread.)

Considering he hasn't been on this board in seven years, that seems unlikely...