Profile: HKS USA designs and builds engines & components. We offer sound performance systems. Our exhaust system features include mandrel bent, bake-coated aluminized steel piping and application specific muffler assemblies to maximize horsepower & torque gains. We offer a complete line of coil over suspension systems ranging from Hipermax LS/LS+ to street & track ready Hipermax RS and the full race Hipermax Drag.