hi, the stage 1 is activated by boost presure and can be only calibrated to turn on and off but full spray is not progressive like stage 2 that it has two nobs one to start boost and one for full boost and yes can be mounted with intercooler but the thing i dont know is that i don't think you can spray cold methanol to the roots directly i think the roots can break with the mixture of cold liquid correct me if i'm wrong!
the other thing is that you have tu put the spray jet 90 degrees to the air flow, i have put them on my friends car stage 1, stage 2 and stage 2 maff on centrifugal chargers and i like them all