HKS looked to Japanese GT Racing when designing the Hi-Power Exhaust System. Taking the lessons learned there, the HKS Hi-Power exhaust uses an offset low restriction muffler design, and minimized bends in the piping to increase exhaust flow and power production. The piping diameter ranges from 55mm to a massive 75mm diameter, depending on application. The mufflers and tips are made from SUS304 stainless steel to prevent against corrosion and fading. Some HKS Hi-Power exhausts are offered with special burnt titanium tips and full SUS303 stainless steel piping as well. In addition to this, a silencer is included on select applications to keep sound levels in check when needed.