[chang-kuao-lo]

Shouldn't both nozzles have the same pressure regardless of what boost pressure triggers them? They are running off the same pump whether a controller or a pressure switch is used, yes?
So, if I understand how the Progressive Controller works, I can run the two nozzle pre and post turbo system having the pre-turbo triggered at say 2-3 psi, and the post-turbo triggered at ~ 6-7 psi.

[Terry Syd]

A controller drops the voltage to the pump in order to drop the flow/pressure. Having both nozzles hooked up and having the controller set at say 3 psi to start the flow means that the pressure would have to be below 200 psi in order to flow less than at full voltage/pressure. The reduced pressure, as I understand it, means that the water droplets would be increased in size. Since I have a pre-turbo nozzle, I want to keep the droplets small to minimise compressor erosion.

By having the pump run at full voltage I keep the pressure high. The pressure switches only determine when and which nozzles get the full pressure. I get full pressure on my pre-turbo nozzle at all times. When I flick on the auxilliary post-turbo nozzle there is a pressure drop in the system. However, it does not stay on for long periods of time and even then there is probably sufficiant pressure to keep everything well atomised.

I recall DevilDoc writing that up to a M3 the pressure in the system stayed above 200 psi.

I have gone for a basic system that works within the parameters of my driving. I could see someone else creating a more complex system to do multiple tasks, however this basic system does everything I want it to do.

[chang-kuao-lo]

So the controller regulates not only when the nozzle(s) open, but the voltage, and pressure, of the pump. That makes a bit more sense now. I think I might try the two pressure switch system.