IAG Performance Equal Length HeadersThe IAG Performance Equal Length Header is the perfect upgrade to boost the performance and power in your 2015 2021 Subaru WRX with the FA20 DIT engine. While the OEM headers restrict the airflow behind the engine port, the collector pipes and the turbo port, IAGs precision engineered header provides a clear path for increased airflow, resulting in more power and greater efficiency. GAME CHANGING UPGRADE In addition to the improvements in airflow, the