by aunt betty » Fri Feb 12, 2016 9:20 am
Hey man, the way you figure out what prop is best is a process.
You need a tachometer.
You run the boat full speed, GPS it to get the speed, write down the RPM's and go to the calculator.
This is where it gets ??? for me.
There is a formula somewhere that helps you convert the prop pitch and RPM's to a theoretical speed.
You compare theoretical to actual and then you can calculate "slip".
Once you know what you got...making adjustments in size gets easy.
Trying to do this without the right tools means "buy a lot of props and figure out which one".
Another thing you should know is that trim and motor height is everything.
I got my little 15hp to go from around 16 to well over 20 just by raising my motor by two inches.
Little stuff adds up to slow you down.
I've heard that it's incredibly stupid to fuck around with a crazy man's head.