CAI, basically gets the air from lower on the ground usually, where it is colder, because it is usually farther away from the heat the engine generates. Colder air, I believe, would carry more oxygen into the cylinder, therefore Cold-Air-Intakes (CAI) usually give better performance, because it can burn more fuel in the cylinder.
Weapon-R intake, is not a cold air intake. I think a WeaponR intake would probably give 5-7HP, while a CAI might give 7-11HP. Of course, those are just theories, you wont feel *much* of a difference, but it will make a cool noise!
