GSC P-D Subaru EJ255/EJ257 (USDM) w/Intake AVCS S1 Cams 268/266 Billet

This package includes a set of GSC Power Division S1 camshafts, designed specifically for the 2004-2007 Subaru Impreza models equipped with the EJ255 or EJ257 USDM engines that feature intake AVCS. These camshafts are crafted from billet material, offering a strong foundation for improved engine performance. The S1 grind features a 268-degree intake duration and a 266-degree exhaust duration, carefully chosen to enhance airflow and power output without requiring extensive modifications to the valvetrain.

The billet construction means these cams are machined from a solid piece of steel, which is a more robust manufacturing method compared to cast cams. This results in greater durability and precision in the lobe profiles. The 268/266 duration figures indicate how long the intake and exhaust valves stay open, and this specific profile is a popular choice for enthusiasts looking for a noticeable improvement in power, especially in the mid-to-upper RPM range, while still maintaining reasonable street manners. They are designed to work with the factory intake AVCS system, allowing for variable timing adjustments that optimize performance across different engine speeds.

When installing these camshafts, it's important to follow the manufacturer's recommended procedures to ensure proper break-in and optimal performance. While these cams are designed as a direct fit for the specified Subaru models, it's always a good idea to consult the installation guide provided by GSC Power Division for any specific tool requirements or critical steps. Keep in mind that these camshafts are not CARB approved and cannot be shipped to California. They are also subject to California's Proposition 65 warning.