I just upped the horsepower again on my 09 Nordic heat, and was wondering what the fast guys are running for prop-shaft depth (inches below the keel) on a single engined v-hull.

Mine is set at 3.5" below the keel, and at this depth, a 5 bladed prop is pretty manditory in order to get slip below 20%.
Slip at this depth is aproximately 13% with a 30 pitch p5x

4 blade props seem to work best at 4"-4.5" below the keel.
Slip at a 4.5" depth is aproximately 12% with a 30 pitch Bravo prop

My Heat is 28 ft long, has a single step, a small pad, and a notched transom.

What is your prop-shaft depth below the keel?

Chris

2.5" below the pad. Single step. ITS box with no notch.

Turns a Bravo 1 with decent slip, 15%

My 28 Pantera with a notched transom was originally set up with a 2" spacer and was 3.5" below the bottom. Propslip was high and I changed to 3" spacer which put it at 4.5". Propslip went down and top speed went up 1-2mph. Cuise speed went up even more. I was running a 26 Bravo 1 prop.

As you have the props, 1" & 1/2" spacers kits would probably be the low cost way to test. Both should cost less than a new 5-blade prop. You can sell what you don't need when you are done testing.

True.. and good point.
I was just curious what others were running for prop depth in faster single engined v-hulls for reference.

Chris