Which Hydrafoil Is Best

M

mrtool2u

Petty Officer 2nd Class
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Jun 15, 2003
Messages
185
I am looking at putting a hydrafoil on my boat,but I am not sure which one would be best. I have a older 16 ft. bass boat with a 1986 90hp Johnson.The hole shot is decent,the speed is ok,,but the porpoising is terrible.With just myself in the boat,I can barely trim up. With some weight in the front,it is a little better.There is stingrays,,sport se,,and doel fin,,and I assume a few more out there.Any and all advice much appreciated.
 
JB

JB

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45,907
Re: Which Hydrafoil Is Best

Howdy Mr Tool.<br /><br />I've had the best performance from the SE Sport 300. I haven't tried them all, but I have tried the Sting-Ray and the Cobra. The Cobra was very close, but twice the bux.<br /><br />Good luck. :)
 
C

cinder1995

Petty Officer 3rd Class
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Jun 8, 2003
Messages
89
Re: Which Hydrafoil Is Best

I agree with JB. I have a Force 120 and the S.E. 300 by Sport Marine worked best for me. I think it's also the biggest one.
 
W

walleyehed

Admiral
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Jun 29, 2003
Messages
6,767
Re: Which Hydrafoil Is Best

If you want a TRUE planing aid that is Hydrodynamicaly designed, buy the stingray XP, the se series is a joke compared to the stingray, and its not a lifting surface, it will just "deflect" water at holeshot speeds. It's hard to explain, but you MUST understand hydrodynamics to understand the difference.<br /> The choice is yours, and you are doing the right thing by asking around, but I know there is very few people that have tried the new XP series. If you choose to buy an XP stingray, AND an SE sport and find you truely like the SE better I will personally buy the XP from you. :D
 
JB

JB

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Re: Which Hydrafoil Is Best

Walleyehed.<br /><br />If you understand hydrodynamics then you understand that the top surface of the StingRay XP must be UNDER the water to provide lift. If it is under the water then you have a very poorly rigged engine.<br /><br />Correctly installed on a properly rigged engine, a hydrofoil serves as an extension of the bottom on plane and provides lift in the same manner. It is on top of the water. When "getting on step" with the engine trimmed in the hydrofoil serves the same effect as trim tabs.<br /><br />I have used both and gotten better results with the SE Sport.
 
J

jasperpso

Seaman Apprentice
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Jun 30, 2003
Messages
42
Re: Which Hydrafoil Is Best

my boat had a Attwood Hydro-Stabilier on it when i got it. Does anyone have experience with this hydrafoil?? I have great speed with a light load, but with heavier loads, my boat wont plane out.. after consulting with a prop shop, they said a new prop the same size might help a little(mine is chewed up some) but that changing the size wouldnt really help my boat.. would a different brand hydrafoil possibly help me? would taking it off help?<br /><br />thanks<br />jason
 
JB

JB

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Re: Which Hydrafoil Is Best

Hi, Jason.<br /><br />You usually get better response if you post a new question in a new topic.<br /><br />To help you we need to know a lot more info.<br /><br />What boat, engine, prop? Where is the AV plate relative to the keel? Is the AV plate parallel with the bottom at zero trim? Do you have power trim? How are you using it?<br /><br />Let us know. Please start a new topic for your new question.<br /><br />Good luck. :)
 
W

walleyehed

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Re: Which Hydrafoil Is Best

JB, I understand hydrodinamics better than most obviously, because a hydrofoil is a planing aid in this case, and if you've ever looked over the back of your boat, or leveled the cav plate setting on the trailer, (unless you are running this on a flat bottom boat), the stingray surface to the outside is STILL BELOW the boat-hence the span of the "hydrofoil".<br /> Your engine would have to be 3 to 4 inches off the transom for the foil to have zero effect at high speed, which would eliminate ANY planing aid, regardless of manufacturer.<br />Come on, guys!!!
 
JB

JB

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Re: Which Hydrafoil Is Best

Hmmmm. You make a point, Walleyehed.<br /><br />I have used hydrofoils only on my Boston Whaler Montauk, which has less than 5 degrees of deadrise at the transom. I can see how a deeper deadrise would keep the tips of the StingRay in the water and perhaps provide lift via the profile.<br /><br />On my boat the StingRay stayed on the surface when on plane, just like the Cobra and the SE Sport 300. My engine is set back 4", with the AV plate level with the keel.<br /><br />Perhaps we are looking at quite different applications and getting different results. I assure you that on my boat and similarly flat stern boats the SE Sport is no "joke".
 
OBJ

OBJ

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Re: Which Hydrafoil Is Best

I think he's got ya' JB. I use a StingRay on my 16' StarCraft with a 90 Rude. No way I can raise the engine to get the foil outta the water and still maintain water flow through the engine. Even when I had my 50 Johnny on it, I had it raised as much as possible and the foil still was under the water. But the rig would pop up very quickly with the 50 sporting a StingRay. Guess some boats are just engineered better than others. But I do love my StarCraft. :D :D <br /><br />Now ya' wanna talk dump foils, lets talk about those ones that bend downward or the "gull wings". Look good but worthless.
 
M

Maximerc

Petty Officer 1st Class
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Jun 26, 2003
Messages
292
Re: Which Hydrafoil Is Best

hummmmm these are mounted to the cavitation plate...so if they run high enough to not effect the boat at high speed ,I would say that your next problem would be cavitation. I have looked at the "v" style and thought that they might be good for just getting the boat up on plane.While keeping drag to a minimum. Possibly they would allow the boat to "bank" a bit more when turning? The Mercury outboard sight claims that these plates cause strange handling... but their law guys make them say that ! I am still learning the handling chariteristics on my Baja SS184 .. It does like to hop when trimed up for speed, but the last time I had it out i was getting better at reading how it was reacting. What is the biggest improvment the plate makes ??
 
OBJ

OBJ

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Re: Which Hydrafoil Is Best

The biggest improvement is getting the rear end of the boat outta the water. Now, not every boat needs one. Some will pop up if ya' breath hard. But some need a little help gettin' outta the hole. A long time ago I read an article on foils. The article ran several of the "name brands" on a rig to see what difference they made. A run without any foils was made to get a base line to compare to. The StingRay foil came out on top as being the best foil to get the rig up and planning with only a small loss in overall speed. I think it was something on the order of 1mph. Now this was several years ago. So with todays hi tech hulls and new tech engines, it's hard to tell what the outcome would be today.<br />I also believe that the foil will help prevent cavitation because it keeps the water on the prop unless you trim to far up. After all, it's just an extension of the anti-cav plate.<br />Just my opinion.
 
Jdeagro

Jdeagro

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Re: Which Hydrafoil Is Best

If hydrofoils were the answer to boat handling issues, the manufacturers of I/Os and Outboards would do the design work and make the cavitation plate bigger. The test that someone was refering to was done by Trailer Boats magazine about four years ago, and not much has changed today.<br />Small boats are no different than small airplanes. Small and large, slow and fast airplanes, have flaps, trim tabs, and rutters. What this does is adjust the airplanes' hull design to compensate for speed, load, wind currents, power (engine), etc. They don't use the engine to adjust attitude. Since air and water are both liquids, boat handling is not much different than an airplane. Since boats are designed with a rigid (non adjustable) hull, they all have one specific speed at which they perform their best. Anything either side of this will be a comprimise. Small boats usually plain easier than bigger boats simply because the power to weight ratio is better. So why don't manufacturers install trim tabs on small boats? Number one reason is expense! So on smaller boats, the manufacturers provide the motor trim which uses the prop to help lift the stern on take off! Why? Because it is safe! If helm controled trim tabs are used on small fast boats the inexperienced driver (or his 10 year old who is helping drive the boat) can mistakenly deploy one trim tabs and cause seriuos handling issues. So between cost and the possibility of missuse helm controlled trim tabs are seldom installed on boats under 22 ft. Hydrofoils are cheap, and they give lift, not much but some. Their effect at low speed is dependent upon the needs of the boat (balance). On Deep V boats lifting the boat from the center ( motor ) can create or exaggerate side to side instability, including pitching hard ( bow down) in turns and chine walk. Porpoising is usually reduced at higher speeds because of the extra lift on the stern, which causes extra bow pressure. This is usaully at the cost of top speed because the motor trim is fighting the stern lift. You never want to adjust boat attitude with the moror, it is simply not efficient. Everything is a comprimise, but boat handling is all about balance and the control of balance. Check out Smart Tabs by Nauticus (Nauticusinc.com)
 
T

tobolamr

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Jul 31, 2003
Messages
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Re: Which Hydrafoil Is Best

Okay, I'm confused now...<br /><br />I have the exact same question for my situation, and from what I've read now, I have these questions:<br /><br />- I thought that in order for a foil to be useful it had to be submerged?<br /><br />- If the Anti-Cavitation (or AV) plate is not under the water, wouldn't you dangerously increase the chance of cavitating/ventilating? Or does that depend upon the outboard and the hull?<br /><br />- What does "setback" refer to? <br /><br />- What does "deadrise" or "dead rise" refer to?<br /><br />I'm sorry for this mess of questions, but I just want to be sure I have things figured out when I go to spend my money on a planing aid for my rig. I'm running an 18hp Evinrude on a 14'6" Starcraft aluminum v-hull, and it almost planes out with 2 people and tackle.<br /><br />Thank you!
 
Jdeagro

Jdeagro

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Re: Which Hydrafoil Is Best

To Tobolamr:<br /><br />With a boat your size and an 18HP motor the more adjustable planing surface the better your low end performance ( getting on plane ). Hydrofoils add additional planing surface ( not adjsutable) and will help a little, but since they are designed to lift all the time ( even after your on plane) they have a tendency to put excess bow pressure on the boat causing it to run slower at top speed. The extra lift usualy does not influence top speed until the boat exceeds 35 MPH.<br />Probably not your concern at this point. True performance would be to use Trim Tabs which will give you more lift at slow speeds ( plane sooner) and adjust to horizontal at higher speeds. See Smart Tabs.<br /><br />Dead rise is the angle if the V bottom. Set back is the distance back from the transom when a motor is mounted on a extention bracket or jack plate.
 
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