Riva Reduction Nozzle

[05rxp05]

Just curious if anyone has used this Reduction Nozzle from riva, what kinda performance does it do for you? Or is it even worth getting.

[JFizzleJR]

General consensus over the years has been that if you pitch for peak RPMs with the 81mm ring, you are going to be about 1 MPH faster than you would if you had done the same for the 83mm stock nozzle diameter. It does sacrifice some acceleration when you shrink the nozzle diameter. The opposite is true when you enlarge the nozzle diameter (speed down, acceleration up). They are a good tool to be able to adjust RPMs for weather variances and seasonal changes.

[05rxp05]

General consensus over the years has been that if you pitch for peak RPMs with the 81mm ring, you are going to be about 1 MPH faster than you would if you had done the same for the 83mm stock nozzle diameter. It does sacrifice some acceleration when you shrink the nozzle diameter. The opposite is true when you enlarge the nozzle diameter (speed down, acceleration up). They are a good tool to be able to adjust RPMs for weather variances and seasonal changes.

When you say pitch, are you saying that the impeller is gonna need to be repitched?

[AZRIVERBOY]

I have them on both my 2008 RX PX and RX TX. They are wonderful especially in Arizona where were 110 and 115° during the summertime you can adjust for RPM adjustments very easily.

[05rxp05]

During the summer here we get maybe 85-90 degree days on average, rarely over that with water temps in the 70+. Good old michigan.

How would this affect my ski.

ATM i have Rear Exit, 14/19, Riva Sponsons and intake grate. Looking to add intake and some other stuff in the next few weeks.

[psycho rxp]

if u were pitched near the limiter, and had a cold snap, shrinking the nozzle size could keep u off the limiter, and gain speed, with out having to pull the prop for every temp change to maintain max performance.