Propeller Slip......
12-30-2004, 11:14 AM
#1
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Propeller Slip......
I thought it might be interesting to talk about propeller slip.
Propeller slip percents are an overall efficiency rating of your hull, drive and drive height and propeller's.
Your propellers efficiency directly effects your top end as we know. So the goal is to find the optimum set-up for your boat. Your current slip numbers will expose potential setup problems and/or propeller problems currently existing on your boat.
Slip is calculated using the following formula:
WOT RPM / gear ratio x pitch / 1056 = Theoretical Speed.
Theoretical speed - actual speed / theoretical speed = % of slip.
Variables that will affect the slip calculation are tach accuracy, the ACTUAL pitch of the prop and speed measuring devices (GPS vs. speedo). The more accurate these reading the more accurate your dial in work and propeller adjustments will be.
So how efficient is your your propeller........................?
Julie
Throttle Up Propellers
727-531-2255
Propeller slip percents are an overall efficiency rating of your hull, drive and drive height and propeller's.
Your propellers efficiency directly effects your top end as we know. So the goal is to find the optimum set-up for your boat. Your current slip numbers will expose potential setup problems and/or propeller problems currently existing on your boat.
Slip is calculated using the following formula:
WOT RPM / gear ratio x pitch / 1056 = Theoretical Speed.
Theoretical speed - actual speed / theoretical speed = % of slip.
Variables that will affect the slip calculation are tach accuracy, the ACTUAL pitch of the prop and speed measuring devices (GPS vs. speedo). The more accurate these reading the more accurate your dial in work and propeller adjustments will be.
So how efficient is your your propeller........................?
Julie
Throttle Up Propellers
727-531-2255
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12-30-2004, 11:46 AM
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Re: Propeller Slip......
How dare you come in here and start a non-controversial post!!! On a side note, I have found that I can lab my own props on the sand bar by my house........ keeps them shiny too!!!
12-30-2004, 12:41 PM
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Re: Propeller Slip......
Yes, I would love to put them on your boat!!!!!! 
Addidtionally, we are going to have, our second annual "Spring Break". Wwith Hydromoitve joining us for testing again, in 2005. You could bring the boat over and we can get her dialed in!
Julie
Addidtionally, we are going to have, our second annual "Spring Break". Wwith Hydromoitve joining us for testing again, in 2005. You could bring the boat over and we can get her dialed in!
Julie
12-30-2004, 10:33 PM
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Re: Propeller Slip......
Julie one question..... I was carrying my props in boxes into my shop and I slipped on ice and fell and broke my a** what is my slip % and what will do for my speed?
Happy new year to you and Matt
Michael
Happy new year to you and Matt
Michael
12-31-2004, 06:56 AM
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Re: Propeller Slip......
Mike,
I don't know if we can help you with that slip calculation. We have not been able to do any real world testing with ice here in FL. You would have to consult some of the more experienced racers in the North. They should have more experience with your situation than we would.
Happy New Year to you as well. Might this be the year that we could expect to see you running Super Stock?????????????????????????????
Matt
I don't know if we can help you with that slip calculation. We have not been able to do any real world testing with ice here in FL. You would have to consult some of the more experienced racers in the North. They should have more experience with your situation than we would.
Happy New Year to you as well. Might this be the year that we could expect to see you running Super Stock?????????????????????????????
Matt
12-31-2004, 02:02 PM
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Re: Propeller Slip......
Julie/Matt
Perhaps you could discuss why it is overall prop performance that is important, not just slip at WOT. As you know, we can get some pretty slip numbers at WOT but our acceleration stinks. Then again, with certain setups, we can get some really great acceleration but run out of prop (and speed) 1/2 mile after the start or coming out of a turn.
Please explain how you would approach this situation.
Perhaps you could discuss why it is overall prop performance that is important, not just slip at WOT. As you know, we can get some pretty slip numbers at WOT but our acceleration stinks. Then again, with certain setups, we can get some really great acceleration but run out of prop (and speed) 1/2 mile after the start or coming out of a turn.
Please explain how you would approach this situation.
