So I can comment on this. I ran a 62t vs the 5 degree up 144/148 nozzle. I felt that the bell shape added more low end but negatively impacted handling.
Three nozzles, shaped as such.
Say you are running the same nozzle bore size and the same impeller, everything is the same except for the shape of the nozzle.
What is the affect of the different nozzle shapes?
I run the 5* up bowl shaped, like one on the left and a none 5* with no bowl shape... Similar bores, all I notice is a handling difference between the 2....
I just noticed the other day that my steering nozzle sticks out further when running a none 5 deg nozzle...which is consistent with your photo between 2 left nozzles
View attachment 404790
Both were opened up to the Max that they could be in an effort to get play with some pump R&D Torrent was doing. We got about 1 more mm out of the 5 degree.Any chance you know the bore sizes, or if they were both unmodified? I think, but I'm not sure, that the bowl shaped one has a larger bore in stock form.
IMO: For 144mm nozzles. The pictures in the paper dont specify transition radius's so it is somewhat difficult to determine exactly.I rank the Diffuser Nozzles by highest Thrust generated as follows:
1) Green due to its best "Streamline" Nozzle Shape, and, Exit Diameter and Constant Diameter Length almost being equal ( Best Thrust @ d/l =1)
2) Silver due to its best "Streamline" Nozzle Shape, and d/l ratio greater than 1 (d/l>1)
3) Blue due to its "Conical" Nozzle Shape, which is inferior to the "Streamline" Shape
Based on this Test Study: http://nopr.niscair.res.in/bitstream/123456789/25593/1/IJEMS 20(6) 476-482.pdf
Relevant reading sections: Figures 2 Nozzle Shapes, Graphs 7, 8 & 9, and Conclusion Paragraphs.
So the Yamaha Rooster Tail is approximately 12ft+ high.
That would represent a Pressure Drop of about 12ft/(2.31ft/psi) of about 5 psi loss.
For a Yamaha 144 mm Diffuser with a 50 mm diameter Exit or about 2 inch:
Exit Area = (Pi x d x d)/4 = (3 x 2 x 2)/4 = 3 square inches
Lost Thrust = 5 pounds per sq. inch x 3 sq, inches = 15 Pounds of Thrust Lost due to Open Tattle Tail Nipple
Stock SuperJet has about 500 Pounds of Thrust. Another 15 Pounds I welcome...
2 “Exponential” nozzles
The JD is a Kawasaki SX(modified) same exponential as my SJ version I can’t find
The R&D That looks like a Seadoo) modified for a Yamaha Pump
This is a great, very informative thread! Has anyone with a FX1 with a 144mm pump swap try a 65v nozzle and/or a 62t nozzle with a Kawasaki X2 adjustable trim/steering nozzle? I'm torn between using a 65V nozzle with the X2 trim or the 62T nozzle with the X2 trim.