AEM determined the engine could see performance gains with a larger diameter intake and less restriction so a larger intake duct was used in conjunction with an AEM ETI module to correct the mass air flow (MAF) signal to the electronic control unit (ECU). The ETI module allows the ECU to maintain the calibration as the factory intended it to be and eliminates a check engine light activation.
Allowing more air to the motor is important for improving power, but the air needs to be clean. AEM includes with the system a Dryflowwashable and reusable air filter (part number21-203DK) offering excellent filtration efficiency against harmful dirt particles.
The 41-1408DS ETI system also utilizes a unique closed airbox design to insulate both the air filter and the Scion FR-S/Subaru BRZ mass air sensor from engine heat. CFD (computational fluid dynamics) analysis was used extensively to ensure maximum flow into the intake air box and to provide even flow distribution around the filter in the air box. Overall the FR-S/BRZ produced an estimated 10 HP and 8.3 lbs./ft. torque @ 6500 RPM when dyno tested with the AEM intake installed.
Some AEM air intakes are not legal for sale or use in California and other states adopting California emission standards while others are CARB exempt and 50 state legal. Check the AEM catalog or website for vehicle applications and specific CARB status for each vehicle and air intake.