{"product_id":"cp-piston-ring-set-for-subaru-ej257-wrx-sti-bore-99-75mm-size-0-25mm-cr-8-2","title":"CP Piston \u0026 Ring Set for Subaru EJ257 WRX STi - Bore (99.75mm) - Size (0.25mm)  - CR (8.2)","description":"\u003cp\u003e\u003cstrong\u003eSKU:\u003c\/strong\u003e \u003cspan itemprop=\"sku\"\u003eSC7422-4\u003c\/span\u003e\u003c\/p\u003e\n\n\u003ch4\u003e\u003cstrong\u003eCP Piston \u0026amp; Ring Set for 2004-2014 Subaru Impreza WRX STI EJ257 - Bore 99.75mm - Size 0.25mm - CR 8.2\u003c\/strong\u003e\u003c\/h4\u003e\n\u003cp\u003eCP forged piston and ring set SC7422-4 delivers reliable power for Subaru EJ257 turbo engines in 2004-2014 Impreza WRX STI models. This 0.25mm oversize kit features 99.75mm bore and 8.2:1 compression ratio to support high-boost setups while ensuring engine durability. Includes matched rings and pins for complete rebuild readiness in performance Subaru builds.\u003c\/p\u003e\n\n\u003ch4\u003eKey Features\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eForged 2618-T61 Alloy:\u003c\/strong\u003e Provides high tensile strength to handle extreme cylinder pressures in turbo EJ257 applications\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAccumulator Groove Design:\u003c\/strong\u003e Reduces ring flutter under high RPM and boost for improved sealing and power retention\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSkirt and Crown Coatings:\u003c\/strong\u003e Anti-friction skirt coating lowers drag, while crown coating protects against detonation in boosted environments\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePrecision Ring Pack:\u003c\/strong\u003e Includes forged steel top ring, cast iron second ring, and three-piece oil ring set for optimal compression and oil control\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e30mm Compression Height:\u003c\/strong\u003e Matches EJ257 specs with 22mm x 1.02mm wrist pins and spiro-locks for direct fit after machining\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch4\u003eProduct Notes\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003eEngine block must be bored and honed to 99.75mm prior to installation\u003c\/li\u003e\n\u003cli\u003ePistons ship balanced as a matched set of four\u003c\/li\u003e\n\u003cli\u003eInspect rods and bearings during rebuild for best results\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch4\u003eInstallation Notes\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003eProfessional installation recommended.\u003c\/li\u003e\n\u003cli\u003eRequires cylinder boring to 99.75mm and ring gap verification per CP guidelines\u003c\/li\u003e\n\u003cli\u003eCompatible with stock EJ257 connecting rods. ARP rod bolts advised for high boost\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch4\u003eThis Part Fits\u003c\/h4\u003e\n\u003ctable border=\"1\"\u003e\n\u003cthead\u003e\n\u003ctr\u003e\n\u003cth\u003eYear\u003c\/th\u003e\n\u003cth\u003eMake\u003c\/th\u003e\n\u003cth\u003eModel\u003c\/th\u003e\n\u003cth\u003eSubmodel\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e2004-2012\u003c\/td\u003e\n\u003ctd\u003eSubaru\u003c\/td\u003e\n\u003ctd\u003eImpreza\u003c\/td\u003e\n\u003ctd\u003eWRX STI\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e2007\u003c\/td\u003e\n\u003ctd\u003eSubaru\u003c\/td\u003e\n\u003ctd\u003eImpreza\u003c\/td\u003e\n\u003ctd\u003eWRX STI Limited\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e2011-2012\u003c\/td\u003e\n\u003ctd\u003eSubaru\u003c\/td\u003e\n\u003ctd\u003eImpreza\u003c\/td\u003e\n\u003ctd\u003eWRX STI Limited\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e2010\u003c\/td\u003e\n\u003ctd\u003eSubaru\u003c\/td\u003e\n\u003ctd\u003eImpreza\u003c\/td\u003e\n\u003ctd\u003eWRX STI Special Edition\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e2013-2014\u003c\/td\u003e\n\u003ctd\u003eSubaru\u003c\/td\u003e\n\u003ctd\u003eImpreza\u003c\/td\u003e\n\u003ctd\u003eWRX STI\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003ch4\u003eWhy Choose CP Pistons?\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003eEngineered for motorsports with decades of piston forging experience\u003c\/li\u003e\n\u003cli\u003eHand-built in the USA for consistent quality in every set\u003c\/li\u003e\n\u003cli\u003eProven design trusted in drag racing and rally Subaru builds\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch4\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eQ:\u003c\/strong\u003e Does this fit all EJ257 engines in 2004-2014 STI models?\u003cbr\u003e\n      \u003cstrong\u003eA:\u003c\/strong\u003e Yes, designed specifically for EJ257 2.5L DOHC turbo in USDM Impreza WRX STI variants after block machining to 99.75mm bore\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eQ:\u003c\/strong\u003e What material are the pistons made from?\u003cbr\u003e\n      \u003cstrong\u003eA:\u003c\/strong\u003e Forged from 2618-T61 aluminum alloy with hard anodized top ring grooves and anti-friction coatings for durability\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eQ:\u003c\/strong\u003e What warranty is included?\u003cbr\u003e\n      \u003cstrong\u003eA:\u003c\/strong\u003e Limited lifetime warranty against manufacturing defects when installed by certified professionals\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch4\u003eShipping \u0026amp; Handling\u003c\/h4\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eMethod:\u003c\/strong\u003e UPS Ground or FedEx Ground\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAvailability:\u003c\/strong\u003e In stock - ships same or next business day\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePackaging:\u003c\/strong\u003e Securely boxed with foam protection\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight:\u003c\/strong\u003e 5.8 lbs\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"CP Pistons","offers":[{"title":"Default Title","offer_id":43720402829391,"sku":"CPPSC7422-4","price":885.15,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1062\/7920\/files\/cp-piston-ring-set-for-subaru-ej257-wrx-sti-bore-99_75mm-size-0_25mm-cr-8_2-cp-pistons.jpg?v=1769636101","url":"https:\/\/www.blackopsautoworks.com\/products\/cp-piston-ring-set-for-subaru-ej257-wrx-sti-bore-99-75mm-size-0-25mm-cr-8-2","provider":"Black Ops Auto Works","version":"1.0","type":"link"}