I have mine set to come on at 6# of boost. At first I had it set to come on at a lower boost and found that it was quenching my spark. At higher boost levels this system behaves differently. Mine came with 2 different sized spray nozzles for low, medium, or (both) high levels of injection. You would have to fiddle with yours to find a happy place but I'm pretty sure you would not need more than is provided for.
My mix is 50/50 ethanol and water. I observe about 100'F intercooling effect at 10# boost. I would question the claims of 60 HP however.
Nice, Cheap crutch for pump gas