HKS HI-POWER DUAL AXLE-BACK EXHAUST: IS250 / IS350 06-UP 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 path. For turbocharged applications, the large and smooth exhaust flow allows greater exhaust velocity for better mid-range boost response and high-RPM power. Naturally aspirated vehicles also benefit from greater exhaust flow capacity as engine tuning levels increase. Certain applications are available in a Silent Hi-Power version which has an inner silencer built into the muffler. Like Drager Exhaust systems, Hi-Power Exhaust systems are made from SUS304 stainless steel muffler and tip assemblies. Depending on the application, Hi-Power muffler tips are 96mm, 115mm and 120mm in diameter, piping diameter ranges from 55mm to 95mm. Special Edition HKS Carbon Titanium Hi-Power Exhaust systems are exclusively available for certain popular applications. These exclusive versions of the Hi-Power Exhaust consist of a carbon fiber wrapped muffler shell, titanium tip, and polished SUS304 stainless steel piping.