bro, the coolant is more then boiling hot! a friend of mine john stupidly try to do it on his integra right after a good 30min drive and as soon as he disscontected one side that coolant was BLASTING everywhere, melted his CF hood alil burnt his arm and taught him a lesson . Aso another friend of me next to him tried to do it on his eclipse i told him not to when its hot he didnt listen an do god was the experience horrible. So that shit is HOT! lol Also guys depending on car and situation it can add maybe 1whp or 2whp. i gained 2whp but it could of been placebo effect but w/e.