CP Piston & Ring Set for Subaru EJ257 WRX STi – Bore (100.5mm) – Size ( 1.0mm) – CR (8.2) Set of 4

SKU: SC7423-4 CP Piston &. Ring Set for 2004-2012 Subaru Impreza WRX STI EJ257 – Bore 100.5mm – Size 1.0mm – CR 8.2 Set of 4 Equip your 2004-2012 Subaru Impreza WRX STI EJ257 engine with this CP forged piston and ring set machined to 100.5mm bore and 1.0mm oversize for rebuilt cylinders. The 8.2:1 compression ratio supports high boost turbo configurations delivering reliable power in demanding track or street applications. This complete set of 4 pistons and rings ensures balanced performance and durability under extreme conditions. Key Features Forged 2618-T61 Alloy: Delivers high strength to handle 50 psi boost levels and resist detonation in turbocharged EJ257 engines 8.2:1 Compression Ratio: Enables safe operation with large turbos and E85 fuel for substantial horsepower gains beyond 600whp 100.5mm Bore 1.0mm Oversize: Precision fit after standard cylinder boring restores compression and allows thicker head gasket for boost Armor Glazed Skirts: Reduces friction by 40% for quieter operation smoother revs and extended cylinder life Accumulator Groove &. Ring Pack: Includes 1.2mm/1.5mm/2.8mm rings with groove design to eliminate ring flutter at 9000 RPM Product Notes Cylinder boring and honing to 100.5mm required prior to installation Pair with CP-Carrillo rods for complete rotating assembly balance Box dimensions 14in x 10in x 8in for secure transit Installation Notes Professional installation recommended. Verify 130.5mm connecting rod length and 79mm stroke compatibility Includes 927 chromoly wrist pins with circlips OEM hardware compatible This Part Fits Year Make Model Submodel 2004-2012 Subaru Impreza WRX STI 2007 Subaru Impreza WRX STI Limited 2011-2012 Subaru Impreza WRX STI Limited 2010 Subaru Impreza WRX STI Special Edition Why Choose CP Pistons? Proven in NHRA Pro Stock and Formula Drift championship engines CNC machined in USA with tolerances under 0.0002 inches Backed by limited lifetime warranty against manufacturing defects Frequently Asked Questions Q: Will this set fit 2013 Subaru STI models? A: Confirmed fit for 2004-2012 EJ257 Impreza WRX STI verify block casting EJ257 turbo Q: What piston weight and compression height? A: Each piston 372g net weight 30mm compression height matched to EJ257 79mm stroke 130.5mm rods Q: What rings are included and warranty details? A: CP premium ring set 1.2/1.5/2.8mm sizes limited lifetime warranty on defects when installed properly Shipping &. Handling Method: UPS Ground or FedEx Availability: In stock – ships same or next business day Packaging: Foam-lined custom box 14 x 10 x 8 inches Weight: 4.8 lbs Reviews There are no reviews yet. Be the first to review “CP Piston & Ring Set for Subaru EJ257 WRX STi – Bore (100.5mm) – Size ( 1.0mm) – CR (8.2) Set of 4” Cancel replyYour email address will not be published. Required fields are marked *Your rating * Rate… Perfect Good Average Not that bad Very poor Your review *Name * Email * Save my name, email, and website in this browser for the next time I comment.