Anyone running a hydrofoil on a stepped hull?
03-28-2022, 03:16 PM
#21
Registered
Trim tabs won’t help after the boats already planed and it doesn’t take much to plane the boat.
For your reading pleasure:
https://www.boatsafe.com/trim-tabs-explanation/
The following 2 users liked this post by techman:
1983ScarabIII (03-28-2022), Sydwayz (03-29-2022)
03-28-2022, 05:11 PM
#22
VIP Member
VIP Member
The 'bow walk' at slow speeds is common, the 'trick' is to NOT touch the steering wheel and let the boat do its thing...yes, it will hunt from starboard to port and back again but it WILL essentially run in a straight line.
The cavitation plate mounted hydrofoils like 'Stingray' and others make will only exacerbate handling issues. Years ago a buddy of mine put one on his Mariah, and damned near killed his entire family when the boat heeled over HARD at speed and tossed everyone out.
The cavitation plate mounted hydrofoils like 'Stingray' and others make will only exacerbate handling issues. Years ago a buddy of mine put one on his Mariah, and damned near killed his entire family when the boat heeled over HARD at speed and tossed everyone out.
__________________
Baja 252 Islander
Baja 252 Islander
03-28-2022, 06:24 PM
#23
Registered
You didn't, but you did say this in that thread. And here you are.
Saying trim tabs aren't effective once on plane.
Saying trim tabs aren't effective once on plane.
Ran 52.8mph last year and 56.7mph today and I might be able to even get a little more out of it since I don’t think the trim was fully down.
Step hulls don’t work like that with trimming.
Trim down to get on plane the. Start trimming up. At least neutral with the hull bottom. Then go to positive trim for speed increase. Now I’m really confused on how plugs made the boat faster. We’re the RPMs the same? Plugs/tuneup usually come into play when the boat isn’t running right. Speed is a simple product of RPM, drive ratio, pitch, and slip. So if you had the same rpm and all else being equal something seems very odd.
03-28-2022, 09:03 PM
#24
03-28-2022, 09:06 PM
#25
Trim tabs are absolutely part of the equation when on plane. They should be installed parallel to the bottom of the boat and effectively lengthen the hull length. While under way you can further lower them to help lift bow of the boat. Drop one side to effectively compensate for a listing condition in head and following seas.. The only time they have no effect is if you run them full "up" and they make no contact with the water, this can help with top speed.
For your reading pleasure:
https://www.boatsafe.com/trim-tabs-explanation/
For your reading pleasure:
https://www.boatsafe.com/trim-tabs-explanation/
https://www.seabornboats.com/what-is-a-stepped-hull/
03-28-2022, 09:07 PM
#26
The 'bow walk' at slow speeds is common, the 'trick' is to NOT touch the steering wheel and let the boat do its thing...yes, it will hunt from starboard to port and back again but it WILL essentially run in a straight line.
The cavitation plate mounted hydrofoils like 'Stingray' and others make will only exacerbate handling issues. Years ago a buddy of mine put one on his Mariah, and damned near killed his entire family when the boat heeled over HARD at speed and tossed everyone out.
The cavitation plate mounted hydrofoils like 'Stingray' and others make will only exacerbate handling issues. Years ago a buddy of mine put one on his Mariah, and damned near killed his entire family when the boat heeled over HARD at speed and tossed everyone out.
03-29-2022, 06:08 AM
#27
Platinum Member
Platinum Member
Need more detailed information, is this a new issue, what speed does it occur (on a plane or not), what trim position is the drive when it occurs, at what speed and trim position does it go away?
03-29-2022, 06:30 AM
#28
Registered
https://www.powerboatlistings.com/view/49850#
Here's a link to a 1990 Senza. Looks like an aggressive step for a 1990 25 foot powerboat. Maybe that's just a handling characteristic of this particular hull. I'd be careful throwing money at it without talking to someone who successfully fixed the issue on the same boat.
Here's a link to a 1990 Senza. Looks like an aggressive step for a 1990 25 foot powerboat. Maybe that's just a handling characteristic of this particular hull. I'd be careful throwing money at it without talking to someone who successfully fixed the issue on the same boat.
03-29-2022, 09:23 AM
#29
Registered
Ahhh, stupid me thought he was talking about a real hydrofoil, not a "whale tale." Sure, I've seen them used successfully in older cigarette straight bottom hulls supposed to help the porpoise quite a bit by providing a bit more lift, but that does not sound like the kind of problems the OP is having.
Max machine cavitation plates
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Smarty (03-29-2022)
03-29-2022, 09:24 AM
#30
Registered
Slight sidetrack but good info for anyone owning these boats. See post #
13 and #14. Have original boat testing article.
Larson Senza Prop questions....
13 and #14. Have original boat testing article.
Larson Senza Prop questions....
