Bulding a motor? Wiseco is proven to be one of the best WRX pistons on the market! Featuring valve pocket designs that allow maximum flow around valve, also allowing oversized valves ang high lift cams to be utilized and piston crown shapes designed to promote maximum intake charge efficiency thru scavenging mixture "cross flow" during intake and exhaust valve overlap. More fuel and air equals more horsepower! Their pistons are designed to optimize squish or quench during compression combustion cycle event, resulting in resistance to detonation and pre-ignition. The end product is longer engine life and increased horsepower potential.