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CP Piston & Ring Set for Subaru EJ257 WRX STi - Bore (99.75mm) - Size (+0.25mm) - CR (10) - Set of 4



CP-Carillo pistons are compatible with oversized valves and high-lift camshafts. Standard features include: Deep valve reliefs to accommodate high lift camshafts, larger valve reliefs for +1mm valve sizes, custom skirt cam and barrel design, accumulator grooves, high strength aluminum forgings, high performance rings, fully CNC machined and balanced to +/- 1 gram, wrist pins included at no additional cost, double pin oilers force fed from oil ring groove, pin lock grooves for easy lock removal, and pin fitting included. *All gram weights provided are approximate and for the bare piston with no hardware attached.


Bore: 100.5mm

Size: 0.040

Over Stroke: 79mm

Rod Length: 130.5mm

Dome/Dish cc's: -6.9

Compression Ratio: 10.0:1

Wrist Pin: 23mm

Weight: 440g

Fitment: 2004-2017 Subaru STI

Actual Product May Vary from Image.


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This product can expose you to chemicals including Lead, which is known to the State of California to cause cancer and birth defects or other reproductive harm. For more information go to