It sat on it for 45 mins with the car idling while they guy tried to figure out a good tach input and then went through 3 pulls and still had a decent amount of slush afterwards. The key is to make sure theres no holes in the bag so it stays filled with water.... if the water leaks out I imagion the plastic could melt. Mine probably lasts so long because my coolant ports in the blower are blocked and the intercooler does a wonderful job of not only cooling the air but also keeping my blower 50+ degrees cooler. My laser temp thingy said my blower was 95* so thats pretty awesome.
