Are most people seeing better results with the heat exchanger/exchangers mounted behind the grille or behind the bumper? Behind the grille you would have the draw of the fans, but you are closer to stuff that is constantly hot, like the radiator. Behind the bumper you don't have any other elements causing the exchanger to heat up, but you don't get the draw of the fans? Which one typically is more effective for lets say lower iats?

 

I dont think it makes a BIG difference. What you should look into is a bigger hx.

 

not just bigger either. look in to the efficiency rating of the hx too. jst make sure air can pass over it wherever you mount it. if it bothers you, you can mount e-fans on the hx.