Top Feed 1050X Fuel Injectors

The Cobb Tuning Top Feed 1050X Fuel Injectors are designed as a direct replacement for factory top-feed injectors in 2007-2021 Subaru WRX STI models equipped with the EJ257 engine and top-feed fuel rail. This set of four injectors delivers a substantial flow rate of 1050cc/min, providing ample fueling capacity for high-power engine builds. As power levels increase, factory injectors can reach their duty cycle limits (80-85%), leading to inconsistent fueling and lean conditions. The 1050X injectors offer increased flow headroom, reducing injector duty cycle and ensuring more reliable fuel delivery, especially critical during forced induction modifications. These injectors are characterized, meaning their flow rates and spray patterns are precisely measured and published. This data is integrated into Cobb's Accesstuner software, allowing a ProTuner to create a custom calibration tailored to the specific behavior of these injectors. The set includes o-rings and installation hardware.