sgr

I have a narrow beam boat (7 foot beam) and it rolls (heels) to the left at high speeds due to prop torque. I'm wondering what is a better setup to minimize the heel?

a 1.36:1 drive ratio with a 23" pitch prop

or

a 1.5:1 drive ratio with a 26" pitch prop

Because of the steeper pitch on the 26", you would expect that it would cause more of a heel if it was turning at the same speed as the 23", but it is turning slower.

Will the amount of heel (torque reaction) be equal on both setups?

My current drive ratio appears to be a 1.36:1 Bravo 1. I'm just wondering if there is any advantage to going to a 1.5:1 ratio before I start investing in some new propellers.

Thanks,
Steve

sgr

.....It's a single engine BTW.....

Formula29

why not use trim tabs to correct?

88Fount33

Do you have a trim tab just behind the prop? My Formula did this until I replaced the flat disk type trim tab with a std. version. The boat then straightened out perfect. No it did not affect speed.

sgr

I do have trim tabs, and yes, I use them. I'm just wondering if there is any way to lessen the amount of tab used and was curious how much affect the drive ratio/prop pitch combination affect the heel.

Thanks,
Steve

sgr

no, there is no trim tab. It's the flat disk.

so this levelled your boat out? There's a thought. It might be worth a try then.

Along the same thought lines, I wonder if a small twist in the skeg could be causing this as well. A new one was welded on a while ago.

Thanks,
Steve

throttleup

What is the WOT rpm? If the rpm is too low that can cause the boat to lean toward the rotation of the prop.

z.zuperboat

Put Sand Bags On The Other Side To See If You Can Get It To Fly Even.then Try Moving Weight Around In The Boat If It Worked.like The Batteries.worked For Me.

aero-offshore

My small beam 7' does the same thing, feels like it's going to roll over if I don't get off the gas. Dos'nt do all the time though. I also have the flat round disc behind the prop and a 1:36 drive. I use a 3 blade chopper style prop.

cobra marty

My drive is mounted 1/2" to the right to offset this.