i don't have any data on the cooling effects of water. i just listened to people who have used alcohol on these cars. straight alcohol has worked great for me. i run 25lbs. of boost with 91 octane and get less than 1 degree of knock retard in 3rd gear. i do have a stretched stock location intercooler though. i would assume you could safely run 20lbs of boost rather safely on straight alcohol. when testing my kit, i gradually raised the boost and my car screamed at 20lbs! while testing at lower boost levels, some kid in a new gto wanted some action. i was a little nervous because i knew my boost was down. i watched my boost gauge while i was embarrassing this kid and it was only going to 16lbs. i know these gto's have 400hp at the motor. i have only a few bolt on parts. bone stock long block with 105k on it. i thought that was pretty good at the low boost levels. even if you can boost to 18lbs. or so, i think you will be very happy with running straight alcohol. i would personally forget about any water. i beleive it's a safer bet for your engine to not mess around with water. just my 2 cents. hope this helps