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I am considering a new set of labbed props for my boat in hopes of picking up a few MPH for the 1-2 poker runs I plan on doing each year. After playing around with the math, I have an idea on where to start. Keep in mind I am only trying to boost the top end speed.

The current set-up: Bravos @ 1.5 with 24p props turning just a tad over 5200 rpm. This gives me a consistent speed of 70 mph which by my calculation is around 11% slip.

The idea: Move to a labbed 3 blade 25p prop to increase speed. I personally don’t have any experience with labbed props but I hear that they usually spin cleaner which increases your RPMs. Going to a 3 blade should probably do the same. I assume that this will make up for the extra pitch and at least keep me in the same RPM range which would yield a theoretical 3 MPH bump in top end speed. If it was able to spin a little faster and get to 5350 RPM I should be closer to a 5-6 MPH increase. The engines are rated at a max RPM of 5500 – is 5350 running it to fast? Is either of these scenarios even a realistic possibility? These increases are also assuming that I can stay within the same general slip range of 10-12%.

I have experimented with reversing my drives (to turn in) and that takes me from a consistent 70 MPH on GPS up to 73-74 MPH. By reversing the drives and changing the props I could see a theoretical 8-10 MPH increase. If you back that down into reality I would hope to see the top speed in the 75-76 range with both changes and really hope/wish for 77 MPH. Reversing the drives to pull the hull out of the water is also part of my assumption. The idea is that using a 3 blade prop would be fine as I wouldn’t need the extra stern lift generated by the 4 blade. Since I would be changing the set-up for the runs and then putting everything back the way it was, I am willing to live with the slower plane times, poor hole-shot and decreased docking manners while in this set-up. Again, it is only about going a bit faster a few times per year.

Does anyone have an opinion on this non-sense? Is this even remotely realistic? Lots of variables to consider and 5-7 mph (7-10%) seems to be a big jump as I wouldn’t be touching the hp/torque numbers. To this point this has just been a math excercise (which doesn't always pan out in the water) so basically what I am wondering is...... Worth a try or a waste of money? Let's hear some thoughts.
 

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I would ask the same questions to Brett @ BBlades or Julie @ ThrottleUp. Matt @ Hydromotive is also very helpful. These people work situations like yours everyday and are experts.
 

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I have had good luck with a labbed revolution plus 4 blade, I would try a 26, the increased rpm from running a rev vs. bravo, and the labbing should let you turn the same rpm with a bigger pitch, but of course run it by brett first, I believe Julie only sells her CNC props now, not sure if she still deals with merc.
 

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Unfortunately Rev4 props only go up to 25 pitch.

MOSCARAB my suggestion is to try and find a set of props to try first and see how your boat reponds. Even if they aren't labbed you will get a good idea of handling and if your boat likes 3 blades.
 
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