JE Pistons SUB STI EJ257 Block w/ EJ20 Head 99.75mm Bore 0.25 Oversize CR 9.5 KIT Set of 4 Pistons

Starting with a 2618 aluminum forging, these JE Pistons are built for serious performance in your Subaru EJ257 block with EJ20 heads. This set is specifically sized at 99.75mm bore, which is 0.25mm oversize from stock, and designed for a 9.5:1 compression ratio, making them a solid choice for builds aiming for improved power and durability under demanding conditions.

JE Pistons uses a proprietary Forged Side Relief (FSR) forging design. This isn't just about saving a little weight; it means reduced skirt width and a shorter wrist pin, which work together to minimize friction and power loss. For applications that benefit from it, an accumulator groove is included to help manage combustion gas pressure, reducing ring flutter and ensuring a consistent seal for reliable power delivery. Many applications also feature a skirt coating that further cuts down on friction and wear, while also helping to quiet down the engine's operation. Every component, from the piston itself to the included JE Pro Seal premium rings and high-quality wrist pins and locks, is manufactured 100% in the USA, ensuring you're getting a well-built part designed for high-demand performance.

This kit is designed specifically for your engine and intended use, optimizing both performance and durability. Please note that these pistons are not CARB approved and cannot be shipped to California. Always refer to the manufacturer's installation instructions for proper fitment and assembly procedures.