pat there is a tech article on columbusdsm.com abouth this as far as spraying any gas co2 no2 on the intercooler I have heard it is a waste. It's based off the principle of metal and what happens when you bring the temps down that low, that fast. My basic understanding is... that when you spray the intercooler with gas it basically keeps heat inside and makes the outside of the metal cold. From dsm stuff, I have heard h2o is the best because when water contacts metal it disapates heat in the form of a gas... like steam which actually brings down temps, verses keeping the iats up and wasting good n2o that should be put in the intake. As far as most of the power gains from n2o I have heard alot n2o gets passed through the engine bay and gets sucked up in the intake. Me personally I am going to do the winshield washer mod were you add a aquarium valve to out going line and buy the garden sprayer nozzle and point it with the intercooler to get bigger spray area. The use of two nozzles can be done but I have read that makes droplets larger, making one as useful as 2. The only thing the sprayer should be used fore is to lower intake air temps and monitoring iat would prove the effectiveness of both. In my opinon though water is free aquarium valve is 5 bucks and nozzle is like 10, 6 feet of 5/16 vacoom is 4-5. So 20 dollars verses....for n20 or co2 setup. It 's cheap easy and if you have rear windshield washer you keep the front to clean the windows. Also comes stock on evos with computer to spray automatically so the engineers at mitsu felt it was worth it. Jus my 2 cents hope it helps