Trim tabs or prop change or what?

[billysboat]

....So I am thinking, I might want trim tabs for my 17'. The pic's are of my project boat, to show the lines and style of the hull. My running boat has a 351 ford motor and a volvo 280 outdrive. I am running a 14x22 pitch 3 blade ss prop.
Here are the issues I am having and am looking for some answers before this years boating season. My rpm's max out at 5100, which I know are to much for the motor, so I may need a prop change or gears (not sure what are in it) for the outdrive. But this boat does jump up out of the water and gets on plane pretty fast and stays there @about 3000 rpm.
I would like a slower cruising speed while staying on plane and still want to get on top quickly and to go a little faster too. Yeah .... I know I want it all. So to my question: What do you recommend?

 

[TJDave]

Re: Trim tabs or prop change or what?

Sounds like you need both to get what you want. Different pitch prop to keep RPM's down at WOT with more top speed. And, trim tabs to lower planing speed and keep the boats ability to get up on plane quickly. JMHO

 

[billysboat]

Re: Trim tabs or prop change or what?

Sounds like you need both to get what you want. Different pitch prop to keep RPM's down at WOT with more top speed. And, trim tabs to lower planing speed and keep the boats ability to get up on plane quickly. JMHO

Can anyone recomend a prop (3 or 4 blade) and what type , size or stlye of trims ?

 

[jayhanig]

Re: Trim tabs or prop change or what?

You probably would do a lot better with a 3 bladed 14" prop with a 25" pitch... that should drop the rpm 500-600 at WOT. You really need to find out for sure what the maximum rpm is for that engine but I'm guessing around 4600.

I'm hardly an authority so if anybody disagrees, feel free to jump in. I'm going on what I've read.

 

[veritas honus]

Re: Trim tabs or prop change or what?

Can anyone recomend a prop (3 or 4 blade) and what type , size or stlye of trims ?

Check out the prop forum. Read the first couple instructional threads for all the necessarry info to supply. You'll get great guidance there.

 

[Chris1956]

Re: Trim tabs or prop change or what?

Trim Tabs may lower your cruising speed. however, after you change the prop to a higher pitch, the power available at each RPM will be lower. I would recommend the prop change and then another trial to see if the cruise speed is low enough.

BTW - that is a low profile speedboat. Why do you want to go slower?