what prop to try now??
#1
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what prop to try now??
I have a formula 271 non step with a single bravo installation. Currently the boat runs 83 at 5600 with a 28 pitch non labbed bravo I. I am installing an imco 12 setback -3" raise extension box and wonder if the hering 5 blade bravo style would be the best place to start.
Before the extension box is installed, I currently have 5 1/4" from propshaft to keel. I am pretty sure the boat won't even come on plane after raising the x dim this much with a 4 blade.
anyone done something similar or have their .02?
Thanks in advance
Before the extension box is installed, I currently have 5 1/4" from propshaft to keel. I am pretty sure the boat won't even come on plane after raising the x dim this much with a 4 blade.
anyone done something similar or have their .02?
Thanks in advance
#2
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I am not sure about your new setup. But I am getting ready to raise mine from a 8" depth to 5". I currently run a labbed 25 Mirage. Did your boat come with the drive set at 5.25"? Did you every try a Mirage on your boat? I will be interested to see what your outcome is. I think because of the angle it will be about 2 1/8" higher. I know some guys are running that high. Check out my thread on "What is your drive height?" under the "drives" section. There is a bunch of good info there.
#3
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I think you can likely get on plane with your prop shaft about 2-2.5 below the keel. Use all your tabs and ease the throttle to as much as 3500-4000 RPM. If you don't like the answer, I would space down 1" and stay with the B1's. The spacer will be less cost than 5-blades and likely this set-up will give you better overall performance.
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I have a formula 271 non step with a single bravo installation. Currently the boat runs 83 at 5600 with a 28 pitch non labbed bravo I. I am installing an imco 12 setback -3" raise extension box and wonder if the hering 5 blade bravo style would be the best place to start.
Before the extension box is installed, I currently have 5 1/4" from propshaft to keel. I am pretty sure the boat won't even come on plane after raising the x dim this much with a 4 blade.
anyone done something similar or have their .02?
Thanks in advance
Before the extension box is installed, I currently have 5 1/4" from propshaft to keel. I am pretty sure the boat won't even come on plane after raising the x dim this much with a 4 blade.
anyone done something similar or have their .02?
Thanks in advance
#6
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thanks for the info. Rob, those Herings are probably going to be a good me, but I only have one screw and I doubt you'd want to separate the pair. How much do you want for them?
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good luck there was a 25ol from germany that picked up a lot from the 3'' raised box went from 74 to 81 with a 525 merc, then he went up 2'' shortie but added a 1'' spacer for its final spot so I think he ended at 3 1/2. I have a konrad with box and am going from 7 5/8s to 3'', I think the boats with steps and notches can go higher under 3. I hope I WON'T NEED TO GO LOWER like 3 1/2''. hate spacers, I plan onstarting with a 30 px5 for base hoping to hit it just right haha. but have a 32b1 also and a 26 b1. if I TURN THE 30 at 6000 to 6400 its perfect. or the 32 at that rpm.