ive found that, on a superjet, a bored nozzle is better than a cone. ive never tried a cone on a 550. i know...... this may not help you much. :dunno:
If you do both, and don't dial in your impeller (get a higher pitch), your top end speed will be affected and you might find the ski cavitating badly...
I bored my OEM nozzle out to 68mm and a quite happy with the difference (I have a straight 15.0 Skat Trak impeller installed too).
Good luck,
Cool. You can always try the freestyle cone later (or make your own as an experiment).
How much do you weigh & what impeller pitch do you currently have?
I'm over 200# so I got the straight 15.0... a smaller rider can get away with a 15.5. If I had the opportunity, I'd personally try to find a 13/18 variable pitch impeller (average is 15.5)...
the cone i would say is useless
what are u trying to do with the ski