JE's billet racing pistons for Subaru EJ257 engines were originally created for Ken Block's Gymkhana STI racecar and are now available to the public. The pistons are 100% CNC machined from high quality 2618-T6 wrought aluminum bar stock and are specifically designed for high horsepower road and drag race engines. The pistons feature internal and external bracing for improved durability and strength. A unique "donut dish" crown and application-specific under crown profile properly redistributes heat and reduces stress concentrations experienced in high horsepower Subaru engines.

Unlike forged pistons, the billet pistons are machined on every surface allowing for all unnecessary weight to be removed during manufacturing. The result of this new process is a weight reduction of up to 32 grams compared to other piston designs! High quality 9310 steel wrist pins and JE Pro Seal Rings are included. For severe racing applications, upgraded Diamond Like Carbon (DLC) coated wrist pins are available.

• 100% CNC machined billet piston
• Specifically designed for high horsepower Subaru racing engines up to 1200hp
• Only 392 grams! Up to 32 grams lighter than other aftermarket pistons
• Manufactured from high quality, certified 2618-T6 aluminum alloy
• Internal and external strut braces
• Premium 9310 steel wrist pins included (.905 x 2.250"), DLC upgrade available
• JE Pro Seal Piston Rings Included (1.2, 1.2, 2.5mm)
• Tru Arc locks for easy installation

• Bore: 99.5mm
• Size: STD
• Stroke: 79mm
• Rod: 130.5mm
• C/D: 30.7mm
• Head CC's: 57
• C/R with .040: 8.8:1
• Dome CC's: -14.1
• Gram: 392
• Footnote: Accepts Turbo / Nitrous / Made To Order
• Skirt: FSR
• Included Ring Set: JG4904-3917