Hydrofoil, needed or not?

[Lavish]

I have a 1975 Mercruiser 140 17' boat. I just replaced my whole drive unit with a SEI SE106 drive. I have yet to try it out. My old outdrive had a hydrofoil installed on it. It will not go onto my SEI drive because the fins it mounts on are thicker on the SEI drive than it was on mine.

Do I need this installed? Did it originaly come on my boat, or was this an add on. Should I try it first without one, then if I have trouble planning, try on on there?

Thanks for any insight!

 

[zbnutcase]

Re: Hydrofoil, needed or not?

It is an add on, and I would run the boat first without it, As every hull is different you may not need it.

 

[JustJason]

Re: Hydrofoil, needed or not?

Before any of your local buddies tell you that you need it, look into Smartabs instead of that pigeon wing.

 

[NelsonQ]

Re: Hydrofoil, needed or not?

Before any of your local buddies tell you that you need it, look into Smartabs instead of that pigeon wing.

I agree with the two posters above.

First try without it, and if you still need something, Smartabs are the better route.

 

[swihartart]

Re: Hydrofoil, needed or not?

I put one on mine as an impulse buy at West Marine. Sport 300 it's called.

My boat, 1977 17' trihull 140.

I noticed that it does plane faster and stay on plane at lower speeds but after reading a ton about the pros and cons I wish I would have got the smart tabs instead.

hydrofoil was $60, had to drill cav plate to mount it, read horror stories of them breaking cav plate from pressures and bad trouble turning at high speeds.
I normally don't go WOT and try not to turn sharp if I am going close to it.


smart tabs are $100 but I read are more stable at all speeds and can't break your cav plate.

Just my opinion...

 

[180shabah]

Re: Hydrofoil, needed or not?

'foils are not a good solution for I/Os. The x-dimension is not adjustable, so ther is no way to get the wing out of the water after planing out. If you really need something, tabs are the only good solution.

 

[Lavish]

Re: Hydrofoil, needed or not?

Well I just got back form the test drive. It worked!! The boat I mean....lol. I just got done doing tons of work to it myself. Anyways, it would plane out at about 3,000 RPM's I didn't get on it too much, as I am breaking in my new outdrive. 3,500 RPM's max. Is this good? Should I be looking to be planing out at a lower RPM. I would plane out, then I could drop down to 2700 RPM's or so, and still be planing. When I let off the throttle it didn't drop right out of plane, unless I put it in nuetral, I could slow down and get back on plane fairly quickly.

So I am probably ok, Smart tabs do look nice tho!!! I will look into them, and forget my wings!

 

[180shabah]

Re: Hydrofoil, needed or not?

I don't have any way to measure actual fuel usage on your boat. Best cruise is usually slightly higher than just minimum plane speed, so that is probably closer to 3500 for you.