|
|
Posts: 20
Location: wild rose, wi | If you read the advertising, these things are supposed to increase performance and fuel effiency of your motor. I guess my question is, do they really work or would it just be a waste of money to install one??? | |
| | |
Posts: 3480
Location: Elk River, Minnesota | Hiya,
Much of that depends on your rig as it sits currently. In most cases the hydrofoil is a benefit when the boat is significantly under-powered, where the motor has a hard time keeping the boat on plane at lower rpm levels. It will help keep the bow down on hole shot and lift the stern when tucked in, then while on plane helps the motor trim up or down for optimum running.
In most, if not all properly powered rigs, I would argue that the hydrofoil is a band-aid for an incorrect set-up between prop, motor height, and boat. If the prop is too high of pitch, it can cause a multitude of issues, most significant of note is porpoising....the prop is just too much to turn and essentially, the bow rises to a point the motor cannot hold it there, and down it comes and repeats the process. This is where many add the hydrofoil to tame the bow.
In an optimum situation for the boat and motor, the anti-ventilation plate is actually riding ABOVE the water line, which would eliminate any effect the hydrofoil has on the handling of the motor.
In my humble opinion, it's an inexpensive "fix" to a rig that is improperly set up.
Steve | |
| | |
| Glad Steve saw this...you can't say it any better than he did...so I won't. | |
| | |
Posts: 20218
Location: oswego, il | I put one on my princecraft and it helped tremendously. It's rated for a 30 and I have a 25 on it. It was slow to plane and not at all with 2 adults and a child. It does now.
Edited by ToddM 3/16/2012 12:33 PM
| |
| | |
Posts: 20
Location: wild rose, wi | thanks for the input guys.. I'm thinking that they don't really cost that much,so if it dozen't work all that well, I won't be out a whole hell of a lot of cash | |
| | |
| Its more than just underpowered hulls causing issues. I can speak from experience, balance is everything!!... But remember all hulls are different and will respond in kind, if you find the right weight distribution, horsepower, prop, etc.... You will find that even an underpowered hull will rock... and powered to the max it will scream..... | |
| | |
Posts: 3480
Location: Elk River, Minnesota | Bronk,
True...but as soon as you drill holes through that anti-ventilation plate, the value of your motor will decrease a bit if, for some reason you look to upgrade after some time.
If you would be so kind, before you do anything, would you be willing to divulge the information on your rig? You may not need it at all depending on your equipment. I'd hate to see you even spend $30 on something that you could put toward a new lure...
Lots of good motor heads on here who can help out on set up, even if you find a different prop would serve the need and end up spending a little more.
Steve | |
| | |
Posts: 20
Location: wild rose, wi | Steve: My boat is a Sylvan 16.5 ft. alum. deep V. It is powered by a 75 horse merc. 2stroke with a 19 pitch prop. the boat is rated for a 90 hp motor. I top out at around 38 or 40 mph. Speed is not really an issue for me.. With people sitting in the back two seats I have a hard time getting the boat to plane off. I am aware that the extra weight is going to change the way my boat handles. I was thinking a hydro foil might help with this problem plus give me the added bonus of better fuel economy. When I'm hauling home a boatload of fish, this can be a real proplem...... | |
| | |
Posts: 3480
Location: Elk River, Minnesota | Hiya,
If memory serves me correctly, the mercury line of motors run either a 2:1 gear ratio or in some cases a 1.85:1 ratio, which I would guess you are over-pitched in your prop, and depending on how the motor sounds, it could be anywhere from 2" too much to possibly 4" too much in pitch.
How does the boat run when you are by yourself? If you punch it, does it take a bit to get up to speed or does it have the ability to essentially throw you back in your seat? When up on plane, how much can you trim the bow? When trimmed in, can you make a fairly sharp turn without ventilating the prop? do you have a tach on your boat and if so, what are the max RPM's that you can reach when you are by yourself with your normal gear?
Also, if two people are in the back seats, some redistribution of bodies would be in order as too much weight in the rear makes it harder for the motor to get the rear of the boat up and out of the hole.
The foil might cost some $30 - $50, which would help a little, but you will lose speed and your hole shot minimally better. With a prop change to a 17 or even a 15 pitch depending on the situation, you will get better hole shot, you will be able to keep the boat on plane with heavier weights, you'll be able to trim up and down with ease, and you are only out another $20 or $30. And...if you do a bit of searching on ebay, you can find boatloads of deals on props for your engine to try different pitches. If one doesn't work, you can easily sell it back off for the same price.
Steve | |
| | |
Posts: 20
Location: wild rose, wi | steve: thanks again for your input.. I,m now leaning towards trying a 17 pitch prop.. we,ll try that and see what happens. Like you said, it won't break the bank and if it works I'll ba a happy camper.. Again, Thanks for your input... | |
| | |
Posts: 208
Location: Sun Prairie, WI | Too much prop! | |
| | |
Posts: 767
Location: Ames, Iowa | Bronk- I have a 16 ft Sylvan with a 40 merc 4 stroke. Definitely underpowered. Wish I had a 60. Was porpoising a lot at any trim after I bought it until I put Nautilus trim tabs on it. Measured very carefully drilled thru the aluminum and sealed properly. They cost me 1.5 mph in speed, but the boat planes up quickly and no bouncing at all. I experimented quite a bit with proper setting and have them set at the lowest setting (#1). Now I have a nice smooth ride. Been a great buy imo. | |
| |
|
hydro-foils