HKS FA24 2.5L High Comp Step 2 Piston Full Kit21004 AT009 Ideal capacity upgrade kit for increasing engine strength when installing a supercharger. Feature POINT 1 Piston Kit To prevent the breakage of the second land, the material employs A2618 material, which has high temperature strength, to achieve a low pin height that eliminates the need for making any service holes. 2 layer molybdenum coated to help reduce friction. The cavity on the piston head optimizes the atomization of direct