^denser air= more power. Same concept as let's say a basketball inflated to ten psi in the summer it will bounce and be hard during winter it feels flat even tho the same amount of air is in there. This means u can inflate the ball to ten psi in the winter and there will be more molecules than ten psi during summer. So if I cool the intake charge let's say 30* that will mean more air at the same psi which is more power.