Thread: Effect of hydrofoil on speed

Well I tried it without the foil and I could get it ti 26 MPH about a 1.5-2 MPH gain but it starts to porpoise once it tops out. I tried numerous trim setting but never found any that reached 26 without the porpoise.
I need a CMC tilt/trim.....sigh, more $$$$.

Check out Bob’s Machine Shop for a trim and tilt. No bad reviews I could ever find and had one now for 4 yrs on a 25 yamaha. Bob's Clamp-on motor tilt and trim (Action Series) 40HP

Had one on a '14 semi-v with a 25hp Johnson. Boat was rated for 25, but that motor was a little heavy for the boat. Without a foil it porpoised so badly that you couldn't go faster than 25. With a foil, on plane within seconds, no porpoising at all, 32mph top speed. If this motor had PTT, I maybe could've gone without the foil.

My current boat has one, I may take it off just to see what difference it makes.

I put a Stingray on my Mercury 115 2 Stroke last year. Hole shot much, much better and no loss on the top end.
It definitely is much more sensitive to tilt / trim adjustments however. Even the smallest changes show at the tach, on and off the rear pad, and sharp turns at cruising speeds. I have also noticed a small change in how the boat steers with the motor trimmed up at some ramps as I approach to load the boat on the trailer, not much but it is a little different. Boat seems to wander a little side to side as I slowly ease up toward the trailer. If the water there is deep enough, the lower down the foot is, the straighter she goes.
Not a deal breaker, just my observations.
Overall, still glad I installed it.
My Dad used to put them on His "Run-a-bout" boats and swore by them.
For those thinking about one, shop around, the price varies greatly!

Appreciate all the input. Thanks.