CP Piston & Ring Set for Subaru EJ255 WRX - Bore (100.0mm) - Size (+0.5mm) - CR (8.4)

If you're rebuilding the engine in your 2006-2012 Subaru Impreza, especially for a performance application, a strong set of pistons is crucial. This forged piston and ring set from CP Pistons is built to handle the demands of a modified EJ255 engine. These pistons are designed with a 100.0mm bore and are 0.5mm oversize, which is common when an engine needs a re-sleeve or has been bored out to clean up the cylinders.

CP Pistons are well-known in the performance world for their robust construction. These are forged from high-strength aluminum alloy, making them significantly stronger and more durable than cast pistons. This strength is essential for engines that see higher boost pressures or more aggressive tuning. The compression ratio for this set is 8.4:1, which is a good target for turbocharged applications where you want to maintain good torque while managing detonation risk. The set includes the pistons and the necessary rings, ready for installation by a qualified mechanic.

When installing these pistons, ensure your engine block has been properly machined to the correct bore size and finish. It's also important to check that all other engine components, like connecting rods and crankshaft, are within spec. This set is designed for the Subaru EJ255 engine found in various models, including the Impreza WRX, and is a solid choice for anyone looking to build a reliable, high-horsepower engine.