HKS 07-09 Mazdaspeed3 Hi-Power catback exhaust31013 BZ001 Inspired and designed from endurance and GT racing in Japan, HKS developed its Hi Power Exhaust system for both turbocharged and naturally aspirated applications. HKS has incorporated this new race inspired offset muffler and piping design into many street applications, which offers a greater flow and higher PRM power gains due to the less restrictive design. This is achieved by eliminating unnecessary bends for the straightest exhaust