JE Pistons Subaru EJ25 Ultra Series 100mm Bore Dia -17.3cc 8.5:1 0.905in Pin - Piston Set

JE Pistons is well-known for building strong, reliable internal engine components, and their Ultra Series pistons are a prime example of that commitment. If you're building a high-performance Subaru EJ25 engine, especially one that will see significant boost, these pistons are designed to handle the extreme cylinder pressures you'll encounter. They are crafted using JE's proprietary Aligned Grain Flow forging technology, which maximizes the material's tensile strength to withstand the rigors of demanding engine builds.

These aren't just basic forged pistons; they come equipped with features typically found in custom-level builds. The thermal barrier crown coating reflects heat back into the combustion chamber, helping to keep piston crown temperatures down and improving the efficiency of exhaust gas scavenging. To further reduce friction and wear on the piston skirts and cylinder walls, a special skirt coating is applied, which also helps to quiet down operation, particularly during a cold start. Lateral gas ports are included to help maintain a solid seal on the top compression ring, even at high RPMs and under high boost conditions. The set also includes premium, thick-wall wrist pins manufactured by Trend Performance in the USA, built to endure the stresses of power-adder applications. Optimized pin oiling features are incorporated to ensure consistent lubrication, reducing heat and friction in the pin and bore area.

This set is specifically designed for a 100mm bore with an 8.5:1 compression ratio, featuring an inverted dome/dish design. All JE Ultra Series pistons are manufactured 100% in the USA, ensuring a high standard of quality control. Please note that these pistons are not CARB approved and cannot be shipped to California.