Thread: Easy prop calculator....

continuousWave.com: Whaler: Reference: Propeller Calculator

I am starting to get the jest of all this stuff.

Theoretically , my boat should run 60 mph at 6000 rpm with 0% slip.

Jack Plates video

Unfortunately 0% slip in water is impossible.

Used to know this stuff pretty well, but from memory, with a rig set up by someone with the knowledge or the $ to experiment, the optimum is 8 to 10%. Drag boats shoot for 5 to 8. Typically, when you bring a boat home from the dealership, about 15 is par before you start tweaking - very few dealers know much at all about boat performance, it's just hit and miss with a lot of them.

Wannabe...

As is, mine calculated out at 16% slip. My understanding is that the higher the rpm, the faster the speed, the less the slip. Ima beginner with wore out training wheels.

Originally Posted by Cane Pole

As is, mine calculated out at 16% slip. My understanding is that the higher the rpm, the faster the speed, the less the slip. Ima beginner with wore out training wheels.

Not true. Below or above the recommended WOT you loose power. Here is some light reading for you. http://books.google.com/books?id=8w0...num=35#PPP1,M1

Originally Posted by IBNFSHN

Not true. Below or above the recommended WOT you loose power. Here is some light reading for you. The Propeller Handbook: The Complete ... - Google Book Search

Shot down..........

I was basing my new found knowledge on this formula of slip. Look like rpm is inversely proportional to slip????????????????

This formula:

.......................... SPEED X RATIO X C
SLIP = 100 X [ 1 - (-------------------) ]
.......................... RPM X PITCH