JE Pistons Subaru EJ25 Ultra Series 99.5mm Bore Dome -7cc 9.5:1 CR - Piston Set

If you're building a high-horsepower Subaru EJ25 engine, especially one that will see significant boost, you need pistons that can handle the extreme cylinder pressures. JE Pistons' Ultra Series forged pistons are made for this kind of demanding application. They're designed to be the strongest, most feature-packed pistons you can get right off the shelf, ready to go into your performance build.

What sets these Ultra Series pistons apart is JE's proprietary Aligned Grain Flow forging technology. This process maximizes the tensile strength of the aluminum, giving them the toughness needed for serious power adder builds. On top of that, they come with custom-level features usually found only in race-specific pistons. The thermal barrier crown coating helps reflect heat, keeping piston crown temperatures down and improving how efficiently exhaust gases are scavenged. The skirt coating reduces friction and wear on the cylinder walls, which also helps quiet things down, especially during a cold start. Plus, lateral gas ports are included to help maintain a solid ring seal even at high RPMs and under high boost, which is crucial for keeping that power consistent.

These pistons are made from 2618 aluminum and feature an inverted dome design, resulting in a 9.5:1 compression ratio with a -7cc dish volume. They come with premium, thick-wall wrist pins manufactured by Trend Performance, built to withstand the rigors of high-performance engines. Every feature on these pistons is optimized for high-horsepower racing engines, and they are made 100% in the USA. Keep in mind these are not CARB approved and cannot be shipped to California.