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Cutting prop Dia?

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Old 10-21-2011, 07:45 PM
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Default Cutting prop Dia?

Instead of labbibg or thinning the blades, what about cutting the diameter down? How muchwould you have to cut for 300 or 400 rpm? What effect would it have in the mid range?
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Old 10-21-2011, 07:54 PM
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I had my 6 bladed props cut down to 15.25 from 15.5. Made a noticeable difference in planing and a slight improvement in the overall ride on my particular boat.
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Old 10-21-2011, 08:26 PM
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running a shorty. Turnning a 28p barvo.it measures 15" in dia. I can spin it 4800-4900rpm. Looking for the best cruise.
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Old 10-21-2011, 08:36 PM
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running a shorty. Turnning a 28p barvo.it measures 15" in dia. I can spin it 4800-4900rpm. Looking for the best cruise.
I think any cutting you do to the od is going to hurt your cruise and efficiancy unless you started out way too big of dia, Smitty
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Old 10-21-2011, 09:07 PM
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I'd try a Maximus. I saw a huge mid range difference over a Bravo.

What's your slip with the bravo?
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Old 10-21-2011, 09:27 PM
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I'd try a Maximus. I saw a huge mid range difference over a Bravo.

What's your slip with the bravo?
Slip is around 14%. Little scared of a five blade. 700#'s of torque through a bravo one.
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Old 10-21-2011, 09:42 PM
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Mike, You already know some of my data and that I ran oversized (15 5/8) 28P maximus. I also had a set of 30P maximus that were 15 1/8. Even though they were only 1/8 less than the Bravos (15 1/4) they would lose bite on the water if I got into anything near about 2 ft chop........they seem great in flat water but in 2 ft one engine kept surging 300-400 rpms. When I turned around letting the wind hit the other side of the boat the rpm surge moved over to the upwind side of the boat. That 1/8 was important apparently.
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Old 10-22-2011, 12:14 AM
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Slip is around 14%. Little scared of a five blade. 700#'s of torque through a bravo one.
i agree with you any 5 blade will hold the water better and lower your slip but it will put more stress on the drive.

Do you have to run a 15" prop? to gain 300-400 rpm the prop won't work right if you cut the diameter that much more. I think your best bet would be to drop down to the next size bravo try a stock 26" 15 1/4" diameter as a baseline and/or comparison to what you have now.

I had good luck with 29" Hydromotive P5X's on a 28 Daytona, gave me same top end as 30" bravos but 3-5 mph better midrange and huge improvement in holeshot. The maximus are just to big, midrange was 10mph more and it would plane out at 13mph (vs 23 with the bravo) but lost 10mph top end.

The P5x is a 15" prop if that is what you have to run.

Unless somebody has the same boat and setup as you their results can only be used as a guide you really need to try some different props and see what works out best for the result you are looking for.
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Old 10-22-2011, 04:57 AM
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I sent you a pm about trying some props, Smitty
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Old 10-22-2011, 06:16 AM
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A thing no one has mentioned is, that the stock B1 28" prop is 15" in dia. I know it says 15.25" but it's only the 32" and 34" that's 15.25". There is also the pitch thing i.e. the 28" being much more of a 27". The Maximus comes in different dia. short and standard tube. So try those in 25" or 26" to get the rpms up.
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