Re: Prop question
How much of a load did you have on board when you did your testing? You need to test with what you consider an average load. If you typically have four folks and gear on board, that's your average. If it's just two of you, that's your average. In both examples, you would likely require a different prop.
Your existing setup is showing about 13% slip so your numbers agree. Understand right off the bat, that two props from two different manufacturers that have the same pitch will perform differently so when you go from aluminum to SS and change pitch at the same time you are entering uncharted territory. Prop selection is not an exact science so some trial and error will likely be necessary since you aren't sure what you want or need. The manufacturer recommends an approximate WOT RPM of about 4600 - 4800 so you can't alter things very much. However, a new 21P prop from the very same manufacturer and design you have now would pick up roughly 400 rpm but that would put you at 4900 rpm at the same top speed. You might try a three blade SS in the 21-22P range. It's hard to say what the net effect of a four blade would have but they generally provide better hole shot at the loss of a little top end than an equivalent 3-blade SS. When considering SS props you will want to work with a prop shop that will let you try before you buy. But when you do decide, be a sport and buy from that shop.
