the formula:

PITCH"/1proprevolution x 1proprevolution/RATIOrevolution x RPMrevolution/1minute x 60minute/1hour x 1foot/12" x 1 mile/5280foot

EQUALS

( PITCH x 1 x RPM x 60 x 1 x 1 ) miles / ( 1 x RATIO x 1 x 1 x 12 x 5280 ) hour

EQUALS

( PITCH x RPM ) miles / ( RATIO x 1056 ) hour



For you, this is: ( 24 x 5400 ) / ( 1.5 x 1056) = 81.8 mph

NOW, this assumes that your prop's TRUE EFFECTIVE pitch is equal to the number stamped on its side. It is never exact, and in some cases pretty far off, but in the case of a Bravo1 prop, it is usually a "good" number to use.

ALSO assumes ZERO prop slip, which is not possible. Try 10 to 12%.

This gives 81.8 x 89% = 72.8mph

Thanks guys.! Thats nice to know... I know this 24 is pretty rough lookin prop.. I wil have to find a nicer 24 or maybe a 25.. I would like WOT to be around 5200 instead of 5400... but I am gonna get this oil issue taking care of first..



on saturaday morning I was on the water 15 minutes and got pulled over by the sherrif.... once he knew I was legal and not just a punk kid he acted a little nicer... we talked about the boat and what I was doing... then he ask .. "so how fast can this go"... I said "don't know still tuning" :D :D :D he rolled his eyes and left.. surprising he didn't say nothing about the exhaust... with 50% of water going out dumps the exhaust is real loud now! :D :D

Well all looks good so far.. First thing we pulled the oil filter to see if we had junk in it.. but it was really clean.. tested the oil pressure sender and it acted wierd.. pulled it out and put in a mechanical gauge... fired her up on the hose and WHALA she has 55 PSI at idle... man I felt alot better.. looks like the sender was the problem.. still have to monitor it to be on the safe side..


does anyone have a 25" 3 blade for sale?

Trav. glad to here all is good. You had us worried there. keep us posted on the speeds. How about a photo of problem child.

Traviss,

Does your Alpha drive have a 1.5 gear ratio?

Ron

Ron.... yes it does have a 1.5:1 gear ratio... :)


Hotboat.... a few photos for ya..

another