JE Pistons Ultra Series Forged Piston Set 83.0mm Bore w/23mm PinUltra Series forged pistons from JE are the industrys strongest, most fully featured pistons available off the shelf. Offered for a wide range of import and sport compact applications from 2JZ to 4G63 and Audi to BMW, Ultra Series pistons feature JEs proprietary Aligned Grain Flow forging technology providing next level tensile strength ideal for the extreme cylinder pressures of power adder engine builds. Equipped with custom level features including