i didn't pay attention to how exactly it worked but focused mainly on the relay, for response though i would assume that it is normally closed, when the pressure switch activates it activates the relay and dumps pressure to the wastegate. i guess i should read it to see exactly how the pressure switch would activate it the other way around to dump full pressure to the wastegate.

 

already pulled the trigger on the parts (using a pressure switch from a water/meth kit) we'll see how well it works and how long it lasts (cost me under $50 total). if it's full of fail then i'll hallman

 

Cool. I like DIY stuff. It's still kind of basic, but it should work.

A couple other notes:
You will probably see a little boost spike over your target pressure, so be wary of that. A lower pressure switch could do the trick if it's too high for your liking.

A standard 3-port solenoid will vent all it's pressure at once. An adjustable control valve can slow the release and smooth out the wastegate's action. It'll take some trial and error to get it right, but it should act similarly to the EBC's signal control.
Here's what I'm talking about.
McMaster-Carr Air Flow Control Valves

 

The pressure switch that I ordered is adjustable

 

tracking and conformation on the parts for next week, we'll see how well it works.

 

solenoid got here, just pressure tested it at 60psi, 0 leakage for ~4 minutes

 

homebrew EBC works pretty damn good. boost picks up quick and holds 17.5-18psi from second gear on (doesnt get enough time to build 18psi in first)