P5Xs lift 35' to New Speeds
#12
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What will 20 total hp do for me? I know that I will probably give up something in the mid range if I have them labbed.
Where did Beak Boater come up with a theoretical speed of 102?
Where did Beak Boater come up with a theoretical speed of 102?
#13
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Great numbers Rebel! I would leave the props alone for now. What were the water conditions, heat & humidity? You could easily gain 200 rpm's in cooler weather.
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#14
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Their are different equations for figuring out slip and speed. This is on that I use RPM X Pitch divided by gear Ratio, divided by 1056=theoritical speed. 5600x31/ 1.5 /= 109.5mph. To find your slip divide your actual speed by your theoritical speed. 98.0/109.5=89.4% effective. Subtract from 100% effective leaves you will 10.6 % slip. Using the same formulas. 5800x31/1.5/1056=113.5, figuring your slip may go down with more accurate blades to 10% or 90% effective. Then 113.5 x 90%= 102.1 mph. Or you can forget all that and go to BAM Marines web site. Go to Knowledge base, then speed calculator and just plug in the numbers and it figures it all out for you!!!! Good luck with your project.
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Their are different equations for figuring out slip and speed. This is on that I use RPM X Pitch divided by gear Ratio, divided by 1056=theoritical speed. 5600x31/ 1.5 /= 109.5mph. To find your slip divide your actual speed by your theoritical speed. 98.0/109.5=89.4% effective. Subtract from 100% effective leaves you will 10.6 % slip. Using the same formulas. 5800x31/1.5/1056=113.5, figuring your slip may go down with more accurate blades to 10% or 90% effective. Then 113.5 x 90%= 102.1 mph. Or you can forget all that and go to BAM Marines web site. Go to Knowledge base, then speed calculator and just plug in the numbers and it figures it all out for you!!!! Good luck with your project.
Actually the Bam computer program is based on the math you state here, it's just more fun to play with than a calculator. Being low tech I prefer the calculator.
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I too would be interested having the bottom blueprinted - don't know what is involved.
I ran my boat in the morning, temp in the low 70s, very little wind, I don't think humidity was too bad. I just don't want to loose any more rpms this summer. Water temp is 80. The water temp climbs to mid to upper 80s in several weeks.
I ran my boat in the morning, temp in the low 70s, very little wind, I don't think humidity was too bad. I just don't want to loose any more rpms this summer. Water temp is 80. The water temp climbs to mid to upper 80s in several weeks.