God, I know I'm going to get beat up for saying such a bad word. But with PWC's, the larger nozzle sizes gives you more bottom end and acceleration. Smaller nozzle sizes incrases top speed but you lose some bottom end /acceleration. You might also want to take into account at what RPM's does your engine produce the most horsepower. A smaller nozzle should bring your RPM's down much like if you increased the pitch of your impeller. If it brings you down too far, you will be both slower on top and off the bottom. I don't know much about the big jets yet, but I'm sure this theroy is similar to PWC's. Hope it helps. Gerrit.
PS. Yeah yeah yeah, I know PWC = People Without Cash, People Without Class, Parollee's Without a Conscience. Ok shoot me. http://free.***boat.net/ubb/wink.gif