Decreasing prop slip on 31/32
 

I have a 93' 31 thunder
5400 rpm
1.5 gear
24 pitch Bravo's
67.5 GPS
@17% slip.

Tried multiple trim positions kinda found the sweet spot I think. To reduce slip are my only options to step up to 5 blades?.

Any advice is appreciated

How much HP?

@400 each
454 mags 365 hp w/ 420 cams, 9.3:1 lil more goodies ect.

17% slip is good! less slip = more speed but harder on the drives,, 5 blades will slow you down you could try a 26 labed 4 blade

I thought 17% was hideous. I just assumed @ 12% would be more like it. I am not to concerned about top speed, would like to get slip down and if I were to use 5 blades I would think my cruise mph would go up some what, most of the time the boat is ran 3000-4000 rpm. But I am up for any thoughts from fellow members

Actually you are closer 15% slip. Bravo props are stamped heavy on pitch and are really .5-1" less than stamped. Use 23.2 for your pitch.
15% slip is pretty decent and about average for most 32's I've read about.

I'm at about 12-13% from cruise through WOT. I would attribute my lower slip numbers to having extension boxes and my props being BBlades labbed for the boat.

Are the drives in the original positions or did you move them up? In other words is it the original X-dimension?

This was the boat designed for outboards. I think the first owner changed his mind and went bravo/big blocks. I beleive he rigged it so I don't know if it is setup like factory. Tonight I will see my propshaft to bottom relationship so we have a idea.

Maybe I am not to far off then. I need a set of props to bring my rpms down to 5200 anyways and would love to pick up midrange 3-4 k cruise mph. First big twin boat so this is my first rodeo. Came from a @90 mph 18' sbc alpha boat lol

If your after mid range speed not top end and want the rpms down then try a 26 bravo 1 and you should get what you want maybe a bit more rpm drop but faster mid range