xerexabante wrote:I don't see any benefit from a CAI sucking hot air from the radiator.
Yep. There's a good reason why auto makers go to the trouble and expense of putting cold air induction on most of their engines.
As a very rough rule of thumb, every 10 degree drop in air intake temperature is good for a several percent increase in horsepower. When you consider that underhood temperatures can 30-70 degrees hotter than ambient air, it's easy to see how drawing in cool outside air can produce significant horsepower gains - not only at full-throttle, but under everyday driving conditions as well.