To maintain the exhaust efficiency, enlargement of the exhaust pipe is usually required; the sound level tends to be increased and low-tone. The exhaust system with a cannon ball-shaped shell usually has lower silencer capacity than an oval-shaped shell; therefore, to reduce the sound level, the pipe diameter is narrowed. However, a narrow pipe diameter also reduces the exhaust efficiency and increase the exhaust pressure.

HKS utilised original unique technology to maintain the exhaust capacity and sound level to meet the JASMA standard which is more severe than the regular safety standard. Inner structure of the silencer was redesigned so the unwanted low exhausts resonance was eliminated, and the sound quality was improved.


* Data is based on the test results of a prototype for RB26.

Exhaust Dress-up Evolution & Safety regulations applicable

• Powerful rear view with the cannon ball-shaped and modern titanium colour tips improve the appearance.
• Tuning cars race in circuits for a time attack have improved the appearance more stylish.
• To maintain large exhaust capacity, the pipe diameter of the exhaust pipe installed on the bottom of a vehicle must be enlarged, and the ground clearance must be narrow. HKS Hi-Power Muffler was designed to maintain sufficient ground clearance with redesigned flanges and layout.