Prop Swap, CT style

I have a 15' trihull with a 1970 Evinrude 60hp engine. I am turning 4800-5000 rpm with load of 2-3 people and a Lab pup aboard. My prop is an OMC aluminum 13.25x17 (391199). This prop is in like new condition. I do not have power trim.<br /><br />I am considering buying a stainless 13.25X15 prop. Michigan Wheel says to drop 2" in pitch when going from an uncupped prop to a cupped prop. Does this mean that the cupped 15 pitch stainless will give the same WOT rpm as the 17 pitch aluminum? What I'm looking for is a better holeshot for sking. I'm also looking for an increased WOT rpm (4800-5000 to low?). Is the answer to buy a cupped stainless 15p or an aluminum 15p prop?<br /><br />I have been considering the Rapture from Michigan Wheel. Any thoughts on this prop, better alturnative in same price range? Thanks

Re: Prop Swap, CT style

Tuna, Id the aluminum prop cupped? Most are. If both are cupped than the lower pitch will add RPM. Therefore, I would think that that 15" pitch (Aluminum or SS) prop will turn about 5400RPM, which is likely acceptable. If you have a lighter load the RPM will be higher!<br /><br />I bought a Rapture for my Sterndrive. I got a great deal on it, which is the reason I bought it. It does work very well, but is it a high performance prop? It is hard to tell on my rig. Some folks like the OMC Raker prop, although I have no experience with them!

Re: Prop Swap, CT style

IMHO, By going from a NON cupped aluminum to a Cupped S/S, you will have to go all the way to a 13 to gain any RPMs.

Re: Prop Swap, CT style

Thanks for the replies. I wish I knew exactly what I have. The prop does not LOOK cupped to me, but then there are varying degrees of cupping. The prop is an OMC #382764 13.25x17 aluminum (posted wrong # earlier). Can someone tell me what I have?<br /><br />How does the Rapture compair to a Stiletto?