Smart Tabs do they work?

[bill 22]

Is anyone using Smart Tabs on a boat with a 3.0L MerCruiser I/O? Do Smart Tabs really help to get a slalom skier out of the water with a low horsepower boat?

The concept of the Smart Tab seems simple but can 140 hp give enough forward thrust so the Smart Tab can give the lift it is supposed to give? I have a 18? bowrider w/ 3.0L MerCruiser and it has trouble getting some skiers up. The size of the skier, size of the ski, and the skill of the skier make all the difference. A skilled skier with the right size ski get up O.K.

Have the lowest pitch prop I can use and stay in my WOT RPM range. The prop is a stainless steel Turbo-1, 14 ?? X 17, three blade. Also, I have a Stingray hydrofoil wing. When I got my new prop I tested it with and without the Stingray and the Stingray seemed to only make a small difference. I used a GPS for speed and a stopwatch and clocked the 0-20mph time. I ran the test the test three or four times each to get the best results.

I am not ready to buy a bigger boat so, would Smart Tabs really help or be a waste of $180?

Bill

 

[QC]

Re: Smart Tabs do they work?

Tabs will help, but don't use them together with the foil. A couple of questions first:

1) Is the bow rising now? or is she staying flat but just doesn't have the power?

2) Do you care about top speed?

3) If no, why are you concerned about WOT RPM?

Yes, staying within the range is important, but if your priority is pulling skiers, and you don't need high speeds, then you could simply go down in pitch and watch your tach closely . . . .

 

[chriscraft254]

Re: Smart Tabs do they work?

IMO, They will be the best $180.00 you have spent on your boat. They are based on the hp you have and the size/weight of your boat, so make sure you get the right size for your boat if you decide to order them. I also think the tabs for your size boat will be in the $125.00 range.

The tabs will help lift from both sides instead of like the foil is lifting directly from the center. The tabs also have more lifting surface and will raise the stern more evenly than a foil. Do not run the foil with the tabs installed. They will definately get your boat on a plain much faster while using less rpms. There are many discussions on this board about them, do a search and you will find all the info you need.

 

[John_S]

Re: Smart Tabs do they work?

If your bow is pointed high, the smart tabs might help some. Usually that can be controlled with trimming in on launch. A lower pitch prop just for skiing, would probably provide better improvement in this particular case. A heavy, inexpeirenced, slalom skier, is like an anchor, until they plane out. You need raw power, and minus an engine upgrade, the lower pitch prop will make more impact, imho. Having both, won't be a bad thing, though. ...and ditch the foil.

 

[bill 22]

Re: Smart Tabs do they work?

1) Is the bow rising now? or is she staying flat but just doesn't have the power?

2) Do you care about top speed?

3) If no, why are you concerned about WOT RPM?

QC, Yes I did try and buy a 15 pitch aluminum prop, it did give me a good holeshot. Because my top speed was so low I got rid of it. The bow is rising very little on takeoff. I always put the trim all the way down/in on takeoff.

As for the foil yes, I would take it off if I get the Smart tabs.

Thanks everyone for the input.

 

[QC]

Re: Smart Tabs do they work?

If the bow is rising very little, then I don't think Tabs will be a magic solution. Sounds like "she needs more power captain".

 

[bill 22]

Re: Smart Tabs do they work?

I was kind a thinking that...she runs real good, I have totally rebuilt the engine just three years ago. The year before that I ripped out the floor and put a new one in. I think I will keep her for a few year and save up for something with more power.

 

[chriscraft254]

Re: Smart Tabs do they work?

Bill, were talking about an I/O here, there is no foil that is going to be able to be set-up right on your outdrive because the hieght of the outdrive can not be adjusted where the foil will be most effective. Even though the boat is coming out of the water ok, the foil is probably causing added drag to the boat once on plain because it is still buried in the water. For it to properly be set-up, it would need to be on an outboard where the anti-ventalation plate rides out of the water when on plain.

I would give the smart tabs a shot, they will give you a more stabile platform, allowing the limited hp that you do have to work more efficiently not just getting out of the water but also after on a plain. With v-hulled boats, innsuring that the boat is on its best running attitude/more trust forward will increase your performance. The foils are very limited in what they provide performance wise and can cause worse performance in some cases because of the simple design and the lack of adjustment. The foil on an I/O simply can not be set-up properly/adjusted to get the proper effect and performance from the foil. Good luck, Budd

 

[bill 22]

Re: Smart Tabs do they work?

Chriscraft & Parker,
Thank you for the input. I was going to read some of the other smart tab forums and revisit this topic closer to spring.

Parker, do you have smart tabs on your boat? If yes, what size boat? My boat handles good, I just want a better hole shot. There are no performance upgrades out there for a 3.0L. I guess my only option to get a better hole shot (other than a lower pitch prop) would be to start throwing stuff overboard to get some weight out of the boat. That would mean the seats have to go because I only take what I need when I go skiing.

 

[QC]

Re: Smart Tabs do they work?

Parker was a spammer

 

[jkust]

Re: Smart Tabs do they work?

Exactly what make and model of boat are you running? Could you have wet foam adding to the weight? Many of the 3.0 owners report plenty of power for towing with narily a complaint.

 

[craze1cars]

Re: Smart Tabs do they work?

My experience with Smart Tabs on an 18 ft 3.0L I/O...some specifics:

Mine was a 1992 Rinker 181 runabout. To make matters worse, the 3.0L in my machine was the wheezy, low-powered 115 hp version offered in the early 90's...not the stronger 135 hp 3.0LX version. With a Hustler aluminum 17 pitch 3 blade ventillated prop, it would run exactly 35 mph at top speed, turning 4,600 rpms (peak for that engine...had 4,200 to 4,600 range spec).

We slalomed behind it constantly....even regularly ran full courses with it....we were all way too cheap to spend $35K on a boat, so we spent $3.5K instead LOL. Worked fantastic, even the wake was manageably small. I'm about 200 lbs. It got me out of the water OK without tabs. Then I added Smart tabs. Then it got me out of the water GREAT. Even with 4 adults and cooler full of beverage on board. The tabs did help on holeshot, absolutely no question about it. Zero to 30 in about 5 seconds without a skiier. As long as I could hang onto the rope for 3 or 4 seconds, I was fully planed out on a slalom without an issue. And as a bonus, the smart tabs helped to flatten my wake even more...which helped slaloming even more. Win/win all the way around from a skiing perspective.

Biill, we still have very little usable info in this thread to help you out. 18 ft 3.0 doesn't tell us much. What kind of boat is this? Year/make/model would be nice. If this is a big wide heavy 1970's tri-hull, or cuddy, your machine will handle and accellerate DRASTICALLY different from my comparatively sleek and light weight 1992 shallow v-hull open bow. What is your current WOT speed, and what RPM is your boat turning with this current 17 pitch prop? Does your current prop have ventillation holes? What elevation are you running at? When you tested that 15 pitch prop, what was your actual top speed? Have you verified the accuracy of your tach? This would all be extremely valuable data to have, to help us point you in the right direction. Smart Tabs can help fix a hull problem. But we don't know if you actually HAVE a hull problem from what has been posted thusfar. For example you might have an excessive weight problem, a prop problem, and outdrive mismatch problem, a tach problem, an engine problem, a fuel problem, an ignition problem...I could go on.

Did you rebuild the engine yourself? Are you that mechanically inclined or did you pay someone to handle it? I ask because I'm curious of state of tune. Comprehensive tune-ups can do wonders, and a STUNNING number of engine replacements/rebuilds (particularly those done on/by old-boat owners on a budget) do NOT include a comprehensive tune-up...whether done at home in the garage, or by a professional marina. If your timing is retarded just 5 degrees, your 140 hp rated motor may be peaking at 110 hp, and a 5 minutes with a timing light might be all you need. Have you checked the ADVANCE timing? So many people with old boats will set base timing and stop there, without revving the motor and checking the function of the advance against specs...so maybe you simply have a weight rusted stuck inside your distributor and it's not advancing as far as it should as RPMS rise....or maybe it's not advancing at at all...again costing you TENS of horsepowers. When you kick the throttle wide open, are your butterflies opening fully flat up & down? Flame arrestor spotless? Choke fully disengaging? What color are your spark plugs?

I will echo what others have said...get rid of the hydrofoil. They are of almost zero value on an I/O. I tried one on my Rinker before getting Smart Tabs, and it was a total waste of money. But to directly answer your question, Smart Tabs were NOT a waste of money on my Rinker for skiing.

As a side note, this may or may not be an issue for you...I did NOT like the Smart Tabs when I started doing some wakeboarding. They made my wake too small and washed out. So I would pull them up for wakeboarding to get a little bit of wake back, especially since wakeboarding takes so much less HP and effort to get out of the water. And eventually we sold the boat and got something bigger and heavier and more powerful for wakeboarding...which has now killed our slalom wake. I do often times still miss that Smart Tab equipped Rinker 3.0...was a GREAT slalom boat.

Hope this rambing helps a little.

 

[skibrain]

Re: Smart Tabs do they work?

Maybe stating the obvious but driver plus spotter only, or driver only was our routine with less hp. Additionally, big baggy swim trunks on the skier act like an anchor.

 

[bill 22]

Re: Smart Tabs do they work?

Here you go...

Boat: 1985 18.5ft Citation, bowrider
Engine: 140hp, 3.0L Merc
Prop: Turbo 1, 17 x 14.25” x 3 blade, with vent holes
WOT: 4400 rpm
WOT speed: 37 mph (driver only, 1/3 tank of gas, no wind, no waves)
Advanced Timing: I have never check this.
Elevation: sea level, but fresh water river
Top speed with 15” pitch prop: ?? (speedometer is broken, now I use Garmin GPS)
Tac accuracy: it is four years old, I could test is with my dwell meter
Wide Open Throttle: Yes, butterflies are straight up/down
Flame arrestor: is clean
Choke full disengaging: I have never checked this, I will need to look in the service manual
Spark plugs: are clean

I am not slamming the 3.0L as a weak engine. Mine runs GREAT and always starts right up on the first try. I do have trouble getting some slalom skiers up. I know skill, weight and size of ski have a BIG impact on how much drag a skier puts on a boat!! If the smart tabs help the holeshot even a little and flatten out the wake some they will be well worth $135.

I did most of the engine work myself but had a pro do the machine work. I am not a pro but a standard do-it-yourself kind of guy. This is what the shop did: rebuilt head, smoothed out cylinder walls, installed new; pistons, rings, main & rod bearings. I put the engine back together (installed; head & gasket, manifold & gasket, new oil pump, new coil, new plugs, new wires) and I put the engine back in the boat. I set the valves and set the timing myself. No, I have not checked the advanced timing. I have a complete service manual. I will need to look up how to check the advanced timing.

Not related but, I also did some work on the out drive. Installed new raw water pump, new hose and replaced all of the boots (shaft, exhaust & shift cable) that boot job was a *****. The shift cable boot was cracked so, I decieded to replace all three at the same time.

As I said above the boat appears to run great but there may be some more things I need to check. I may need to start a new forum Merc section “How to do a complete tune up on 3.0?” I am glad to get feed back from someone that use smart tabs on a I/O ski boat and not from someone that put them on a fishing boat or big cruiser.

Thank you everyone for the help,

 

[jkust]

Re: Smart Tabs do they work?

That 140hp is not the prop hp like you see today. Anybody know what the prop hp of the OP's engine is. You will notice why the 3.0 of today are only 130hp. When you replace the floor, did you gain any performance from removing a lot of water weight?

 

[bill 22]

Re: Smart Tabs do they work?

Maybe stating the obvious but driver plus spotter only, or driver only was our routine with less hp. Additionally, big baggy swim trunks on the skier act like an anchor.

Skibrain,
Yes, I have also experienced the drag car parachute effect of the baggy shorts. Most of the time when I ski I am the only one in the boat or just one spotter.
When I go skiing after work during the week I normally go with just one ski buddy. I stopped taking everything with me in an attempt to lighten the load (combo skis, kneeboard, wakeboard, big cooler). When we go on the weekend with more people I try to let the women sunbathe on the beach and watch the extra gear.

 

[QC]

Re: Smart Tabs do they work?

That 140hp is not the prop hp like you see today. Anybody know what the prop hp of the OP's engine is.

I am guessing 115 to 120.

 

[bill 22]

Re: Smart Tabs do they work?

When you replace the floor, did you gain any performance from removing a lot of water weight?

No, the performance was the same with the new floor. I did not find any wet foam or any foam under the floor.

 

[BSnB]

Re: Smart Tabs do they work?

I replaced the foil on my 20ft deep V 305 V-8 IO with the Smart Tabs a couple of years ago. My boat's fairly heavy and had a fair amount of bow rise with the foil. Once I installed the Smart Tabs and removed the foil, my hole shot improved and the bow didn't rise as much. At WOT my speed increased without trimming the engine out as far which i believe improved my top end as well. Another benefit I discovered is that she turns like she's on rails at much higher speed than with the foil. Better hole shot, lower planning speed, higher top end and improved cornering...all together, the best thing I ever did.

 

[bill 22]

Re: Smart Tabs do they work?

Another benefit I discovered is that she turns like she's on rails at much higher speed than with the foil. Better hole shot, lower planning speed, higher top end and improved cornering...all together, the best thing I ever did.

Sounds like a win..win..for the smart tabs!