OK, say you have a worn or sloppy clearanced pump, nothing too bad just the normal been around a while type pump on a 50-60 MPH WOT type hull / setup.  You totally go through it with a stuffer, etc. (keeping the same cut) what kind of MPH gain are you going to see on the top end? 5 mph? 10 mph? 30 MPH? ... Usually the only cure for performance is more HP :-)

The talk of HP and jets made me start wondering best case what are you going to see.  A sloppy jet is going to let the engine rev more, potentially allowing the same water CFM out the back in theory (though I don't know if that theory holds up)...

Marcs repy is pretty typical of what happens after a rebuild . Drop in RPM's because the pump is loading better and as a result more MPH . Depending on how bad a shape your pump is in , you'll feel the diffrence all around .

-beerjet-

X2 on all counts, won't get a huge increase in top speed, may get a bit more "bite" out of the hole, reduced RPM, but beyond that I wouldn't expect too much.

On the stuffer, it literally just makes the pump more efficient, most times help, not hurt, but heard horror stories, nothing serious though.

A bunch of power won't neccisarily make a huge speed gain either, everything needs to be upgraded to work with each other, think of a 600 HP big block but a worn pump and engine makes best power at 6500 RPM, wont work. Build the pump to the motor and the motor to the pump, that being said, if your cards are played right, build the pump and get the boat working with less HP, then when you get the HP, should work well.

GT

Wouldn't this have been better suited for the "Jet Pumps" section of SoCal.


Why do you necessarily want to go with the same impeller cut? I'm going to assume A cut. How much HP is the engine? A different cut "might" help it out a lot. Especially, if you don't have a lot of HP.

Good luck.

  

-beerjet-