Brian, the radiator thing is something I saw a few times and an idea I borrowed from the Chaparral, McLaren and Lola's of that era. (Have a look at the radiator in those cars) There are a few more components that go with that sort of system but I left them off on this build. After all, it's a Model and Representation and not a replica and won't be turning real laps. Besides, most that see it won't know what they are looking at anyway. Since water weighs 8.34 pounds per gallon, the idea is to get that weight a little lower to help the CG and with under hood clearance as with the other cars I mentioned. During some slow pace laps or sitting in the pits a fan would help but while at speed there is plenty of air flow to cool. There is more to all this but we are building models, not the real thing so no need to go into all the details and theories. Since I built this one with some of my "twists" I added it. I had seen this years ago and thought it was a pretty cool idea. The cars I saw this on never ran over 210 degrees even in a 200 lapper and those guys were running up front and winning so they got something right. I am not sure about this system on dirt. You would have to figure out how to keep things from clogging up with mud to keep the air flow going but if you were using Methanol for fuel that might help some. The blue Av-Gas was nice but when you could get your hands on some of the Red stuff, that was the bomb.