AEM STI COLD AIR KIT (36HP+)

AEM is proud to introduce its new Cold Air Induction System for the 2008+ Subaru Impreza WRX and WRX STI (part # 21-478WR). The largest power gains for the 21-478WR (tested on STI) are 36 horsepower at 5,300 RPM and 35 lbs/ft of torque at 5,300 RPM as measured Harman Motive’s All-Wheel-Drive Mustang Dynamometer. The same kit tested on a WRX model generated 13 horsepower at 5,500 RPM and 14 lbs/ft of torque at 4,100 RPM on Harman Motive’s All-Wheel-Drive Mustang Dynamometer.

AEM Cold Air intakes are dyno-tested against the competition to deliver unsurpassed performance. Each system is tuned on the dyno to deliver maximum torque and horsepower, and monitor OBDII sensors, Mass Airflow sensor (MAF) signal voltage and fuel trims during this process to ensure that all readings are within OEM parameters, eliminating the chance of a throwing a check engine light.

All Cold Air intakes are constructed of CNC, mandrel-bent 6063 aluminum, and feature reinforced, TIG-welded brackets and fittings for maximum durability. AEM also includes a heavy-duty steel heatshield with a powdercoated black finish, a complete hardware kit and comprehensive installation instructions with every Cold Air intake system. The 21-478WR comes in a special wrinkle-red finish specifically for the Subaru Impreza models. In addition of the standard 6063-aluminum pipe, AEM includes a built-in air straightener for this application, which keeps CELs away and fuel trims in line with the factory.

All AEM intakes include AEM’s revolutionary DRYFLOW synthetic performance air filter; the first cleanable, reusable performance air filter that does not require oiling to filter and trap dirt and contaminants.