CP Piston & Ring Set for Subaru EJ20 WRX - Bore (92.5mm) - Size (+0.5mm) - Compression Ratio (8.5)

This is a set of forged pistons and rings from CP Pistons, specifically made for the 2002-2005 Subaru Impreza WRX with the EJ20 engine. If you're rebuilding the engine in your WRX, especially if you're looking to handle more power or are dealing with worn-out original pistons, a set of high-performance forged pistons like these is a critical component. They are designed to be a direct replacement for your stock pistons, but with a stronger, more durable construction.

CP Pistons are well-known in the performance engine world for their robust construction. These pistons are forged from high-strength aluminum alloy, which makes them significantly stronger and more resistant to detonation and fatigue than cast pistons. This particular set has a 92.5mm bore, meaning they are 0.5mm larger than the factory bore size, which is common when re-sleeving or honing an engine block during a rebuild. The 8.5:1 compression ratio is a notable detail; it's slightly lower than stock, which is often beneficial when using forced induction (like a turbocharger) as it helps prevent pre-ignition and allows for more boost pressure. This setup is ideal for building a reliable, high-horsepower engine.

When you're undertaking an engine rebuild of this caliber, it's important to ensure all components are properly matched. These pistons are designed to work with the factory connecting rods and crankshaft, but you'll want to confirm clearances and ring gap according to CP Pistons' specifications. This set includes the pistons and the necessary rings, ready for installation by a qualified mechanic. Please note that these pistons are not CARB approved and cannot be shipped to California.