JE Pistons and Rings 100 Bore 79mm Stroke 9.5:1 Comp Subaru WRX / STI EJ257 2004-2021

Part #: 310938. JE piston designs are crafted for extreme use, even in professional competitions for your Subaru WRX and STI. High compression ratios, high boost, or heavy nitrous use call for the high - tensile 2618 aluminum alloy. Fitment: SUBARU EJ257 TIME ATTACK 'FSR'. Note: Now compatible with OEM or aftermarket rods! Some blocks may need clearance for stroker applications. Features: No deburring or prep needed for dome/dish; 2618 T6 high - tensile forged aluminum; Smooth radii on dome and dishes for great flame travel; 1.2 x 1.2 x 2.5mm ring widths; Comes with .905 x 2.500 (Round Forging) and .905 x 2.250” (FSR Forging) straight - wall carbon steel wrist pin; Pin fitting and Tru - Arc locks included; Package contains 4 pistons and 4 rings.

These JE pistons and rings are designed for your 2004 - 2021 Subaru WRX or STI EJ257. Installation is straightforward, but make sure to check if your engine block needs any clearance adjustments, especially for stroker applications. The pistons come ready to use, so no deburring or extra preparation of the dome or dish is required. When using, keep in mind that they are built to handle high compression ratios, high boost, and heavy nitrous use. For maintenance, regularly check the rings and pistons for wear. If you notice any abnormal performance, it's a good idea to have them inspected by a professional. Remember, these parts are compatible with both OEM and aftermarket rods, giving you more flexibility.