Hydrofoil (whaletale) fins on an outboard with power tilt/trim...

[datastream]

...useful or useless??

85 Force85 - I've heard the fins are for motors without pwr t/t to help in plaining and whatnot. I'm not sure how to use the t/t except that I try to keep the fins parallel with the water surface from start out to WOT...and to tilt the motor for trailering.

Im curious if the trim function can replace the fins and if the fins are actually working against the trim.

If someone could educate me on the trim function, how to use it properly (i'm guessing at it), and if the fins can be removed to improve top end...which is about 30mph with two people on Bayliner 1800 B/R.

Big thanks in advance...

 

[Frank Acampora]

Re: Hydrofoil (whaletale) fins on an outboard with power tilt/trim...

Hydrofoils are useful or useless! Depending upon power and hull.

Power trim sets the angle of the "cavitation" plate in relation to the bottom of the boat. Tucking it in will apply lift to the transom for a quicker hole shot and faster time-to-plane. After the hull is on plane, moving trim out (or up) will raise the bow and reduce the wetted surface of the hull, thus increasing speed--until you hit the "sweet spot." Pass it and the prop will ventilate. Some hulls can use all the "up" trim travel available and others can not.

A hydro-foil can help time-to-plane on heavy underpowered boats but can reduce top speed. The best thing to do is keep an open mind and try the boat with and without it. It only takes 4 bolts and 10 minutes to attach or remove it.

 

[datastream]

Re: Hydrofoil (whaletale) fins on an outboard with power tilt/trim...

Thanks Frank. I'm headed to the lake today with foils removed. Not sure what to expect, but i'm thinking my boat qualifies as 'heavy, underpowered', as you described.

I'll update the results and if I have time I may run without them then put them back on to compare.

Thanks for the info on the t/t also. : )