quicker planing

vipzach

Lieutenant
Joined
Feb 15, 2005
Messages
1,283
I was just wondering if I could get some opinions/thoughts on hydrofoils. Are they a benefit. They sound good on the packages. I am just wanting to get a quicker plane when we are skiing and wakeboarding. They seem like an inexpensive benefit, but are they just that? I have a 91 VIP 18ft, Merc 3.0 and Alpha I Gen I drive.<br />This may be the wrong place to ask this question, wasn't sure where else to ask.<br />Thanks, Zach
 

QC

Supreme Mariner
Joined
Mar 22, 2005
Messages
22,783
Re: quicker planing

Vip-man. I have never liked these things because they usually cut top speed. Also, if they were that good, Merc, Volvo et al would sell them as an option. I have never used them though.<br /><br />I would spend my money on trim tabs. Ask anybody who has them; they work wonders and can be used to correct a variety of things including time to plane.
 

craze1cars

Lieutenant Commander
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Dec 26, 2004
Messages
1,822
Re: quicker planing

I can speak from one experience. Water-skiing for the past 15 years behind my dad's 70hp outboard 16 foot Crestliner was a real chore, and deepwater starts on a slalom were impossible, until we put on a StingRay. So as I skiier, I can attest that it helped that boat for sure. And if you do a search on this site for "foil" or "hydrofoil" you'll find a LOT of different opinions and experiences to read about.<br /><br />You have a very similar boat to mine...a 1992 Rinker 18 foot open bow with a 3.0 Mercruiser. And I've been wondering the same thing. So I decided to get scientific on this one. Last weekend, after finding the perfect trim position that maximized top speed, I grabbed a stopwatch and did three zero to 30 runs with a GPS speedo and 2 people on the boat. Got there in about 10 to 10.5 seconds each time. And top speed was pretty consistently about 36 mph (I have a 14 x 17 prop for accelleration, that limits me quite a bit on the top.)<br /><br />So...I bought a Sting Ray for mine and bolted it on. And next time I go out I'll find my new perfect trim position, make sure I have 2 people on board again, and then do my zero to 30 and top speed runs again and will report my exact findings. If I shave a second or so off on accelleration I'll be tickled to death. And top speed is useless to me but I'll check it out of curiosity. <br /><br />But unfortunately you'll have to wait...I might not hit the water again for a few weeks depending on how my weekends work out. We'll see what happens. I figure a $50 bill is about the cheapest experiment I'll ever be able to do on a boat...and if it doesn't work out like I hoped, I can probably get 80% of my money back on Ebay.
 

ryrepsak

Cadet
Joined
Apr 10, 2005
Messages
11
Re: quicker planing

I have ordered a StingRay hydrofoil and when i put it on i will let you know if it was worth the $50. I wakeboard with my boat and i was hoping it would help to get it out of the hole faster.
 

tommays

Admiral
Joined
Jul 4, 2004
Messages
6,768
Re: quicker planing

the foil works great on my 20 ft cuddy cabin with a 3.0 and it was the only thing you could do cheep until smart tabs came out <br /><br />i here many good things about smart tabs and think they are worth thinking about also<br /><br />pretty much every sterndrive boat made is stern heavy and needs something to help with the holeshot and allow lower planeing speeds when its rough<br /><br /><br />tommays
 

Jdeagro

iboats.com Partner
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Jul 30, 2003
Messages
1,682
Re: quicker planing

When boaters say that "I don't mind loosing some top speed (either from a prop change lower pitch or a hydrofoil) because I have gained low end performance", I cringe. <br /><br />Let me phrase it differently - "I don't mind spending more money for gas, because I have gained low end performance". <br /><br />If the motor needs to work longer, or more to achieve the same results, in the end you use more fuel with an added wear factor.<br /><br />Tommays quote at the bottom of his post says it all. The hull performance is key to the over all performance of the boat. The propulsion system is the other half of the formula. Don't keep ignoring the hull efficiency.<br /><br />The disadvantage to hydrofoils is they become an extension of the hull that can not be adjusted, and it was never designed into the overall package from the beginning. They do help the boat get out of the hole quicker (there is more lifting surface) but in most situations they will slow the boat down at high speeds, because they continue to lift the stern at higher speeds. This drives the bow into the water which then requires more trim (out) to bring the bow up. This use of the prop reduces the efficiency because it is running at an angle trying to compensate for the excessive stern lift of the hydrofoil. If the boat runs slower, it is not efficient over all including intermediate speed handling.<br /><br />Trim Tabs work because they are not fixed, they can be adjusted (or self adjust) to suite the changing conditions. This extension of the hull can be made (adjusted) to work toward the most efficient performance under all of the changing conditions (speed, wind, weight, balance, water etc.).<br /><br />Changing prop pitch (lower) solely to achieve a better hole shot, is also a sacrifice in efficiency as it increases the RPMs at all speeds. Again more fuel. <br /><br />Get the hull to work for you first, then re-prop or not.
 

vipzach

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Joined
Feb 15, 2005
Messages
1,283
Re: quicker planing

nautijohn, I understand what your smart tabs do and they sound like a great thing. I am just wondering what others thought about hydrofoils and any real adverse reations to putting them on. They seem to be an inexpensive help on holeshots, which is what I want because we ski and wakeboard alot. I do not spend much time trying to see how fast my boat will go. If I lose a mile or two per hour on the top end, OK, if it helps get someone out of the water faster.
 

craze1cars

Lieutenant Commander
Joined
Dec 26, 2004
Messages
1,822
Re: quicker planing

Originally posted by nautiJohn:<br />[QB] "I don't mind spending more money for gas, because I have gained low end performance". <br /><br /><br />No reason to cringe, this is exactly how I feel...I'm a waterskiier who is overworking a boat with a little motor, so I'm glad to spend more money on gas to gain some low end performance. Besides, if I'm pinching pennies on gas, I'm in the wrong sport for sure! ;) <br /><br />After reading all your past posts of hydrofoil bashing, I was kind of wondering if you'd show up when this topic came up again.<br /><br />I don't know all the specific rules on this site, but isn't there some rule against advertising on these forums? Maybe not.<br /><br />Regardless, I'm doing nothing more than expermienting. It's cheaper and easier to experiment with a foil than with your trim tabs, so I'm doing that first. (No need to reply with your long term gas wasting analysis calculations here...we've all read them already) Enough people have claimed some success with foils that I feel it's worth a shot. After I've experimented, I'll report my findings for the benefit of others and maybe try some trim tabs instead if I don't like the results. <br /><br />I'm sure your product works great, not trying to dispute that at all, just sharing my thought process. Happy day!<br /><br /><br />EDIT: After re-reading my post, I sound like kind of a jerk, don't I? My sincere apologies. Nautijohn please understand that I do respect and understand your opinion and I apologize if I came across a little rough. I'm glad there are so many different people out here sharing their opinions and expertise.
 

tommays

Admiral
Joined
Jul 4, 2004
Messages
6,768
Re: quicker planing

most boats mine for sure with a 3.0 are UNDER POWERED but they get the job done at a low cost<br /><br />a 14 x 19 prop allows the correct 4800 rpm WOT and a gps speed of 42 mph but if you put 6 people or 1050 # of stuff the boat will NOT come on plane with out people moveing around no matter what kind of trim tab system you have <br /><br />the motor does not have low end power to turn that prop out of the hole period with a fully loaded boat<br /><br />so in my case you do the only thing you can, go to a smaller prop<br /><br /> in my case a 14 x 17 the motor can spin this prop and the boat comes on plane in a matter of seconds with everybody saftely sitting in there seats<br /><br />you are now limited in top speed but if the motor is to small its to small <br /><br />with this setup and a hydrofoil i can run fully loaded at 26 mpg gps at about 3800 rpm and get about 4 MPG<br /><br /> the boat is really quiet and has much less vibration then trying to make it turn a prop that really is to big <br /><br /><br />i have run the boat with and with out the hydrofoil and when you at speed it just runs better with a prop that is to small if you go by the book but if you went by the book it would have at least a 4.3 in it any way<br /><br />tommays
 

Jdeagro

iboats.com Partner
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Jul 30, 2003
Messages
1,682
Re: quicker planing

Hi Guys;<br /><br />If you notice it was not me that mentioned our product in this post, I am trying to be informative but it is hard. I also do not take the comments personally. Hydrofoils have been one of the few remedies available for smaller boats for many years. What really makes me cringe is the dealers (and I ran into one yesterday at one of the national chains) that say one of two things " our boats don't need trim tabs because our hull is different" or "if the boat needs trim tabs there is something wrong with the hull". It tells me that they haven't got a clue as to how and why boats handle the way they do. All you need to do is look at the sales numbers for Hydrofoils, and transom wedges, and extra Props to realize that hull design that is fixed is limited. <br /><br />As for bashing hydrofoils, I was simply saying that "anything" that slows the boat down or makes it run more (RPMs) is adding cost to the operation of the boat. You guys say that 'on one hand the hydrofoil is desirable because its purchase price (cost) is cheap, on the other hand the cost of extra fuel is OK.' Sorry that dog don't hunt.<br /><br />I know it is easier to drill hole in you motor than your transom, and experimenting with $50.00 than with $190.00. That is why we have a performance satisfaction guarantee. <br /><br />You will experience improved planing ability with the hydrofoil (or just about any added planing surface). However, this is most likely to happen at the expense of other handling characteristics. Trim Tabs have more surface (and are at a deployed angle) therefore they are more effective.<br /><br />Let's set economy issue aside for the moment. If the hydrofoil limits top speed then it is interesting to know why, especially when they claim more top speed. The common thought is that they create extra drag on the drive unit. I maintain that this extra drag is so minimal that there is a more logical reason. It is excessive lift after the boat is on plane and cruising. By the way this is not the case for boats that run under 25 mph. <br /><br />The excessive lift drives the bow down, and in order to attain the proper running attitude it is necessary to trim the motor out more. This runs the prop at an angle which compromises prop bite and speed. <br /><br />Other handling issues occur. On V hull boats, the added lift to the stern from the hydrofoil is dead center. This tends to reduce the port to starboard stability. Similar to a teeter totter the boat balance is skewed more to the center (keel). In sharp turns the bow wants to dive (cut) into the turn and the boat will lean hard. Most boaters learn to anticipate this and back off the throttle in the turn then accelerate out. Most of the time the boat comes off plane.<br /><br />Trim tabs lift from both sides of the boat, and can be (or automatically) adjusted for improved stability. <br /><br />And since someone else brought up Smart Tabs, it is a fact that properly adjusted they always improve top speed, as wells as handling. Simply because they can be "tuned" to the individual boat. There is never more lift than what they are adjusted for regardless of the speed. As for Hole Shot, they are twice as effective. Actually there is no hole shot because there is no hole! Sounds like a sales pitch and unrealistic claims --- ask someone who has used them..
 

tommays

Admiral
Joined
Jul 4, 2004
Messages
6,768
Re: quicker planing

I have long term real world water sport experience with and underpowered 3.0 boat and a correct craft with a real nice 351 that will rip 8 peoples arms off the correct craft will pull a wake boarder at about 2200 rpm stern drive will still be thinking about moving at that rpm <br /> <br /> The boats are right there in my avatar most wake boarders are looking for performance below 20 mph a lot of people like to trick at 13 to 16 mph if this is what you want to do with a stern drive 3.0 boat it’s a waste of time to even think about top speed the best efficiency or all that other stuff it just not going to happen.<br /><br />Just put on a small prop get some trim help with something and have fun at these low speeds I don’t think the hydrofoil is going to cost you any gas money its just going to let you have the most fun for the least money<br /><br />If top speed is your goal that’s a whole different ball game and the hydrofoil is not the best pick <br /><br />i find in general that the things that work on bigger motors just dont happen on my 3.0 but i still have a GREAT time with it<br /><br /><br />
f479e698.jpg
<br /><br />tommays
 

craze1cars

Lieutenant Commander
Joined
Dec 26, 2004
Messages
1,822
Re: quicker planing

Well, I got out this weekend with the foil installed. Just a reminder I run a 1992 Rinker 181, 18 ft open bow with a 3.0 Mercruiser....about a 2,000 lb boat. Unfortunately I didn't have an exact duplicate load as with my first test, 2nd test added one person and a fairly heavy cooler that wasn't there the first time...so I'd have to say I was about 200 lbs heavier than during my first test.<br /><br />I can honestly say I didn't really notice any significant gain or loss with the StingRay foil compared to not having it. My zero to 30 times was within 1/2 second with/without it, sometimes slower and sometimes quicker...likely due to stopwatch operator margin of error, and my top speed was 1 mph slower, but again I was 200 lbs heavier so I'm not sure I can blame that on the foil.<br /><br />Steering was fine...didn't notice any great amout of lean in hard turns different than without it.<br /><br />The one big change...I did notice a significant difference in how sensitive the boat was to trim changes. MUCH more sensitive with the foil, which I personally feel is a good thing. You have a very clear and distinct sweet spot, which changes with your speed, when I had the foil. It also could stay on plane easily at a slightly slower speed. Water not warm enough to try skiing behind it yet. Might do another on/off experiment with me on deepwater slalom start, and then I'll know for sure whether I want it or not.<br /><br />Was it worth buying? Probably not. Will I take it off? Probably not.<br /><br />How's that for a sit on the fence product review?
 

Wotknot

Petty Officer 1st Class
Joined
Aug 6, 2002
Messages
310
Re: quicker planing

"Water not warm enough to try skiing behind it yet."<br /><br />I learned to slalom by kicking a ski off while being pulled in MARCH.....fell twice, stayed up the 3rd time. Come on, Craze....Be strong... :D <br />Oh, btw, that was about 32 years ago, too.
 

craze1cars

Lieutenant Commander
Joined
Dec 26, 2004
Messages
1,822
Re: quicker planing

Ha. I thought someone may catch onto that remark! I guess I ain't strong. Back when I was young and stupid, I managed to get out once on a fluke 70 degree day in December (I'm in Indiana, water temp was upper 30's...and had access to a wetsuit that day.) If you trust your driver to not leave you in the water too long, it can certaily be done...frankly, if I had a good driver I probably would have been talked into it yesterday, but was out with only 2 ladies who had never driven a boat before, don't have a wetsuit, and didn't feel too motivated to teach lessons while floating and freezing! So I just sat in the boat and enjoyed the scenery. In due time...next weekend may be break-even time for me. Now that I've aged a decade or two, I usually shoot for 65 degree water temp, saw 63 on the thermometer yesterday!<br /><br />Thanks for the push...see ya!
 

craze1cars

Lieutenant Commander
Joined
Dec 26, 2004
Messages
1,822
Re: quicker planing

OK...for the benefit of others, I'll continue my saga with the StingRay hydrofoil. Decided to brave the cold and did some experimenting with foil on & off during deep-water slalom starts behind my wheezy 3.0 stern drive. Frankly, I felt it was a touch easier for me to get out of the water WITHOUT the foil. And a few more zero to 30 runs and top speed runs mixed in, I've come to the determination that the StingRay Hydrofoil did NOT help my sterndrive and I would NOT recommend it to others with a similar setup. However, with my past experience with StingRays on low powered outboard boats, I can say that I found they DO help those types of boats. But I will still not recommend their particular product to ANYONE any longer due to one reason...poor customer service.<br /><br />Their website offers a "No hassle money back guarantee" if not satisfied for ANY reason. So after determining I was finally not satisfied, I called the manufacturer and said I wanted them to make good on their money back guarantee. They said return it to the dealer...mail order company refused to take it back as product is now opened and used. I told MFR this issue, they said please talk to our tech department about your installation. I did, we talked, they told me to shim it up higher with stainless fender washers to get it out of the water a little more, I did, it didn't help. I called and said AGAIN I wanted to make good on their "NO HASSLE money back guarantee" (which by now had already become a hassle.) Finally, after 3 more phone calls & emails, someone there flat out told me that their corporate office makes it very difficult for those products to be sent directly to the factory for refunds, but they'd research and get back with me. Suddenly the return phone calls and emails from them came to a dead halt. So now I'm DONE.<br /><br />NO HASSLE? HA!<br /><br />So this company has lost my business forever, and I'm posting my disappointing experience on the WWW for all to see. And the StingRay? It's permanantly off the boat and on Ebay right now....hopefully someone with an outboard can use it better than I could with my sterndrive and can offset some of my small financial loss for me.<br /><br />In conclusion, do I think hydrofoils are bad? No. Not for an outboard that needs help planing. But it didn't work as advertised on my stern-drive, that's for sure. And if you're considering trying a foil, don't buy a StingRay...buy a competitors product instead...one that stands behind their written guarantees. <br /><br />So there ya go...trim tabs, here I come! Starting to research my options there to see how they'll work for me. Will update if/when that project comes to fruition. In the meantime, I'm goin' boating! Time to stop working on this thing and just enjoy it for the summer....<br /><br />See ya!
 

Jilly - 5

Seaman
Joined
Jul 28, 2003
Messages
74
Re: quicker planing

Instead of all that "trimming and tabbing", sounds like you just want a day's fun pulling one or more persons behind you, with one or more persons in the boat. You want your boat to dig out fast and forcefully, and don't need any top end that brings tears into everyones' eyes. Suggestion: get a four blade 14 3/4 x 16. They're on ebay used, or new for $129. You'll love a 4x, for hole-shot, and midrange. You'll lose a ltlle top end. But they pull like a monster, like your engine is on a whole new torque curve. And for your size boat and the day's fun you desire, who cares about fuel efficiency. Just get all the fun-lovers to chip in!
 

vipzach

Lieutenant
Joined
Feb 15, 2005
Messages
1,283
Re: quicker planing

THANKYOU craze1, that is exactly what I wanted to know. It sucks you wasted time with it, but I appreciate it. Like you I am still thinking about smart tabs, or maybe a four blade prop like the other guys have suggested. Once again though, THANKYOU for the test! Lets try to enjoy our summer! Zach :)
 

DaveM

Petty Officer 1st Class
Joined
Feb 27, 2002
Messages
308
Re: quicker planing

Hey Craze,<br /><br />I would like to thank you for all the effort you put into researching this and taking the time to inform the rest of us. There has been a lot of dicussion of fins vs. tabs, but it never seemed to apply to my application. You gave me the information I was looking for.<br /><br />And for the tab dudes, I figured that tabs were for boats larger than my 20' V6 4.3L runabout. However, I would probably go with tabs if I didn't have my eye on a tournament skier. Vah-room.
 

craze1cars

Lieutenant Commander
Joined
Dec 26, 2004
Messages
1,822
Re: quicker planing

Glad to have helped anyone in some small way. Just bear in mind that my opinion is only that of one person. A few others here have mentioned they liked foils on their stern-drives....so I don't want to pretend to have all the answers.<br /><br />Honestly I don't think of it as a waste of my time. I'm always looking for a little "edge" in just about everything I do, and if it takes some experimentation, money, and guesswork, that's all part of the game that i enjoy. Sometimes I find success, sometimes I don't...I'm a hobby car racer and very occasional snowmobile racer, so I guess that's in my blood and I have a lot of patience for that sort of thing.<br /><br />And Jilly, thanx for the prop suggestion....I'm experimenting with props right now, but like everything else, I'm trying to do it on the cheap....I currently have a 3 blade 14 1/4 x 17 on it, and it over-revs at WOT by about 200 rpms already, so it pulls outta the hole fairly quick and I can't go any less than that without really over-shooting my range. A 4 blade of any type is not one of the 4 props I've managed to gather up at the moment, but it's in the back of my head as a strong possibility and I'll likely try it sometime when an inexpensive opportunity arises. Appreciate the recommendation. Besides, I gotta be realistic...it's just a 3.0 so I'm not expecting to find a magic bullet, but every little bit helps my old bones get ripped outta the water! I really enjoy this forum when I can't be on the water. Later!
 

mikebc

Petty Officer 2nd Class
Joined
Apr 10, 2005
Messages
111
Re: quicker planing

Craze,<br /> Thanks for doing all the leg work for me, I have almost the same boat / year / motor / etc. with the same needs as you. I was ready to order one, but decided to wait for your results, glad I did! I have heard of a five bladed prop that a few people really liked for getting the boat & skiier out of the water, without loosing much or any top end. I also think with the right prop you wouldn't overrev, just planting a seed here! Let us know if you find a good solution, as I would most likely copy you! Thanks again, and just think, you saved me from adding to the profit of a company that does not desire it. Thanks!
 
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