JE Pistons Ultra Series Subaru EJ257 Piston Set - 99.75mm Bore, 9.5:1 CR (Set of 4) 361331

Designed for the extreme cylinder pressures of high-boost racing builds, the JE Pistons Ultra Series is engineered for Subaru EJ257 engines. These forged pistons utilize proprietary Aligned Grain Flow technology to maximize tensile strength and durability beyond standard off-the-shelf components.

This set comes fully featured with professional-grade upgrades, including a ceramic-based thermal barrier crown coating to manage heat and improve exhaust scavenging, and lateral gas ports to maintain a high-pressure ring seal during high-RPM operation. To reduce friction and cold-start wear, the skirts are finished with a specialized coating. Each piston is paired with a premium thick-wall wrist pin manufactured by Trend Performance to handle the stresses of significant power-adder applications.

• Fits Subaru EJ257 engines
• Bore Size: 99.75mm
• Compression Ratio: 9.5:1
• Proprietary Aligned Grain Flow forging technology for superior strength
• Thermal Barrier Crown Coating reflects heat into the combustion chamber
• Lateral gas ports for optimized top-ring sealing
• Friction-reducing skirt coating for longevity and quieter operation
• Optimized pin oiling for reduced heat and wear
• Includes Trend Performance high-strength thick-wall wrist pins
• Manufactured 100% in the USA
• Manufacturer Part Number: 361331