Seems like this may be uncharted territory. Has anyone done this and noted the differances on their boats?
Not really, the shear amount of information needed to figure this out is mind boggling.
To come up with an actual flow, there are some pieces of info needed that are difficult, but not impossible to obtain.
The thing you have to remember is that flow is totally irrelevant, velocity and area are what your looking for (sort of the same, but easier to get the info).
The area is a piece of cheese...Simply the exit area of the nozzle.....
The velocity is different.....Just because the impeller is "bigger" does not mean the pump will move more water......Only if the engine is turning the same rpm. Which it shouldn't if impeller is bigger and moving more water (theoretically), you could very well drop the motor out of the curve and move less water.
If you know the coefficiant value (CV) and the pressures at certain points you can do some pretty awsome math, but the information is worthless IMHO.....
I can tell you that going from a B to an A in the race boat made the engine labor and would not get to peak torque resulting in a loss of top end speed, it took me by suprise to say the least....
Why do you want to go with a AA? I thought the motor you had was good for over 5K RPM...The only way you could convince me to go with a AA is if you could overrev an A. Plan on losing 500 to 700 RPM.
Ok so the chart tells me what HP, what RPM's but it doesn't say anything I could see
about the flow out the jet?
I have a 12JE with an A impeller turning 5200 RPM's
If I put on my AA impeller and it turns the RPM's at the rated HP what will that do to flow?
How would that calculate to Speed with everything else being the same? Meaning same boat
just change the impeller.
Will the boat have a higher top end or lower? 
Gonna say the same top speed or slightly slower if the power plant needs the 5200 RPM to get the rated HP..
Shit, I think I just confused myself.....
GT
