We recently had a customer with a 28' Lavey Craft-Party Prowler come to Quality Performance in search of more performance out of his existing boat. The boat was equipped with a Mercury Racing 525 with a Bravo 1XR drive spinning a 24 pitch Bravo prop. This particular boat was rigged a SmartCraft SC5000 screen which is a great tool as you can have access instantly to all kinds of information including fuel consumption. The customers complaint was that the boat had a hard time rolling over onto plane, he had to keep the engine RPM at 3500 or above to maintain a plane, and finally that he was getting 1.2-1.4mpg in the mid range cruising speeds.
We went out and tested the boat and found that the boat would hit 64 mph at 5200 RPM yielding a 19% prop slip. When
Next we installed a two inch drive spacer to lower our X Dimension and go out to see how the boat reacted to it. Right off the bat there was dramatic changes! The boat now comes out of the hole with no problems, and acceleration in the mid range was noticeably increased. The prop slip has now decreased again to 11%, but we are still hitting the rev limiter at a slight increase of 62mph at 5450 RPM. One of the more notable side effects is now the boat is able to be trimmed as it should be. With increased trim it will now carry the bow, and our efficiency robbing rooster tail (in this application) has finally disappeared.
If you are wondering if there is room for improvement on your current setup, there almost always is a way to get more out of what you currently have. Feel free to give us a call or to see if we can help you dial it in! We have an extensive selection of props on hand, and our team has the tools and the expertise to often make some minor adjustments and yield major gains.
Quality Performance Marine
(written by RiverDave)