CP Piston & Ring Set for Subaru EJ257 WRX STi - 100.5mm Bore +0.5mm Size 9.0 CR *Single Piston Only*

CP Pistons is well-known for making strong internal engine components for performance applications. This single forged piston is built for the Subaru EJ257 engine found in WRX STi models. It features a 100.5mm bore, which is 0.5mm larger than stock, and a 9.0:1 compression ratio. This piston is designed to handle the demands of a high-performance engine build.

Forged pistons like this one are generally stronger and more durable than cast pistons, making them a popular choice for builds that see hard use or require more power. The 9.0:1 compression ratio is a common target for modified EJ257 engines, offering a good balance for pump gas or E85 tuning. This part is sold individually, so be sure to order the correct quantity for your engine rebuild.