A cold air intake kit is one of the best upgrades you can do to your Subaru WRX STI. Turbo systems love to get a lot of air in and then move that air out as efficient as possible. So to improve the air intake, Agency Power has this complete cold air intake system with heat shield for the Subaru WRX STI. Made here in the USA, the Agency Power Cold Air Intake utilizes a roto-molded intake tube that has been designed to increase airflow and performance without the need of an ecu tune. Each kit utilizes a high flow cone air filter to not only breathe better than factory, but is reusable for the life of the vehicle. This high flow cylindrical air filter features a much improved flow rate over stock and designed to catch more particles compared to a paper mesh design. With the new air filter, your turbocharger can breathe better than the factory intake allows. This is noticeable as you step on the accelerator and hear the turbo work (sucking air noise). Release the throttle and the factory blow off valve noise (whoosh) is more audible and keeps you entertained through the gears! The aluminum heat shield helps keep the air forced in from the front of the STI directly on to the filter. Used as a barrier between the engine and the filter, it also helps reduce intake temperatures. The heat shields are powder coated black and features the Agency Power "AP" logo. As tested on Mustang AWD Dyno the Agency Power Cold Air Intake on the Subaru WRX STI made +26WHP and +34 WTQ.