Good info. I've looked a little farther into this too.

I combined the data available at spray.com (page 17 of their unijet fine atomizing nozzle data sheet) with actual measured ml/min experimental data gathered by autospeed for various nozzles. I used this to estimate pressures that are seen in the line for nozzles ranging from 0.6 to 4.


For a size 0.6 unijet, it flows 65 ml/min on this pump. I estimate that the line pressure is therefore around 100psi.

For a size 3 unijet, it flows 230 ml/min on the pump, so I estimate the line pressure drops to around 60 psi.

For a size 4 unijet, it flows 260 ml/min, so the pressure drops even further to around 50 psi.

2gnt: '99 RS-T, killed by a toyota, pending rebuild...
Daily: Volt
Daily #2: '99 EVG ebike- STOLEN by PEDRO