Doel Fin Hydrofoil

[bustermin]

just curious, i see a lot of motors with those Doel Fin Hydrofoil fins installed. do they really make a difference? i have a 75hp Chrysler with manual tilt, is it worth putting one of these on? a friend of mine gave me one that he found at a garage sale, it brand new in the package but neither of us have ever used on before. it doesnt look like it would be very hard to install just drill and bolt maybe 15 mins. of work, just didnt know if it was gonna make any difference for my motor. maybe the fact that i do see a lot of them should answer my question, and i did see the other posts about this topic but they dont specify manual tilt and i just didnt know if the fact that i have manual tilt makes a difference. thanks

 

[roscoe]

Re: Doel Fin Hydrofoil

What exactly are you hoping it will do?
If you are underpowered, you will still be underpowered.
If the motor is mounted to low or too high, it will still be mounted too low/high.
If the boat is azz heavy, it will still be azz heavy, but MAY level out a little.

You may lose top end speed if your set up is not right.

Or it may be the miracle cure that all the motor manufacturers forgot to put on their motors at the factory.

 

[bustermin]

Re: Doel Fin Hydrofoil

i wasnt hoping it would do anything, i do not have any complaints with the set up i currently have with the exception of no power tilt. i was simply wondering if it was worth putting on the motor i have, since i have one of these fins laying around.

 

[JB]

Re: Doel Fin Hydrofoil

Hydrofoils, correctly rigged, are a simple solution to several possible annoyances, but they may also become annoyances themselves.

What they do is stealthily increase the boats planing surface when at the correct trim angle. This can allow quicker and lower speed planing and less fuel consumption.

On the other hand they increase drag and can interfere with precise turns when on plane.

I have never gotten acceptable results with a hydrofoil on a non-PT&T (fixed trim) outboard. If the trim angle is not ideal they reduce speed and can even make it harder to plane.

I have always gotten good results on PT&T outboards when properly rigged and when trim is carefully monitored.

Bottom Line? If you rig and use it correctly on a PT&T outboard it is great. If not it is a big pain you know where.

Oh, and FWIW, smart tabs do everything better than hydrofoils.

 

[bustermin]

Re: Doel Fin Hydrofoil

yea, i was leaning towards the smart tabs myself but i just figured i would see if anyone with a manual tilt enging had tried the doel-fins. thanks guys

 

[john from md]

Re: Doel Fin Hydrofoil

Doel fins have some advantage to jumping up on a plane when towing skiers but their disadvantages negate the advantages.

In some situations, you can actually lose control of the boat with a hydrofoil installed.

A better solution would be to invest in a set of smart tabs. They will get you up on a plane fast and don't have the bad characteristics of the hydrofoil.

Regards,

John

 

[jddens]

Re: Doel Fin Hydrofoil

I've been watching this thread and have a question....I have a hydofoil on my 85hp 1710 trophy.....it was on the boat when i bought it. Boat pops on plane in about 30 feet with 19 pitch prop. I don't have power trim and have the pin in the closest position to the transom. If i move the pin out at all I start proposing but do seem to get alittle high top end.......now for the question....what are smart tabs and where can I get more information on them.........Thanks...........John

 

[john from md]

Re: Doel Fin Hydrofoil

iboats.com/nauticustrimtabs

Smart tabs are tabs that use air filled shock struts that automatically adjust for power and turns. They don't use a hydraulic or electric motor and are simple to install. The guy who owns the business will give you all the help you need.

I have them on my latest boat, a Bayliner 1600 which used to have a Doel Fin. The fin causes imputs on the steering since it is attached to the motor. The smart tabs don't put any pressure on the steering and will get you up as fast and at slower speeds. I can stay on a plane down to 13 miles an hour with me and my fishing equipment on the boat. That equates to big gas savings too.

John