Originally posted by 98SmeLS
Putting cold air into your engine makes more power because cold air is denser than warm air. That means more oxygen, more combustion, more power.
The CAI doesn't give more power because of colder air. Your engine bay is actually pretty cool with air moving around in there etc. If it was giving more power because of cooler air, then you would see a gain accross that whole dyno.
Rather going from SRI to CAI simply works like changing your intake manifold, you're swapping where you want your power. The CAI is going to give you the extra power at the AEM hump as you can see in the dyno. The SRI is going to give you extra power way up top (higher than most of our tegs will ever rev), up past 8.5k. At that range, the CAI's power just drops off. So essentially it has to do with the velocity of the air coming into the engine and the effect of the length of the tubing... the temperature differences aren't enough to make any sort of real world difference.