HKS Super Turbo Muffler Cat-Back Exhaust System - Subaru WRX / STI GDB (2004-2007)
The HKS Super Turbo Muffler Cat-Back Exhaust System is designed for the Subaru WRX and STI GDB (2004–2007), delivering maximum performance without compromising everyday driving comfort. Drawing on HKS's extensive expertise in turbocharged engines, the system combines high exhaust flow, low back pressure, and a carefully tuned exhaust note that meets the demands of both performance enthusiasts and daily drivers.
The Super Turbo Muffler series was developed around three key objectives: maximum exhaust efficiency, reduced sound pressure, and an engine-specific exhaust note. The result is an exhaust system that performs equally well on stock engines and high-performance builds equipped with upgraded turbochargers.
The optimized design improves exhaust flow and reduces back pressure, allowing the turbocharged Subaru boxer engine to breathe more efficiently. This delivers quicker throttle response, improved exhaust scavenging, and a broader, more usable powerband while maximizing the engine's performance potential.
The exhaust note has been carefully engineered specifically for Subaru's boxer engine, producing a deep, sporty, and well-balanced tone without excessive noise. The system also complies with JASMA noise regulations, making it an excellent choice for enthusiasts who want outstanding performance while maintaining a refined driving experience.
Designed as a direct bolt-on replacement, the exhaust system provides OEM-style fitment for straightforward installation.
Features
- Fits the Subaru WRX / STI GDB (2004–2007).
- Complete Super Turbo Muffler cat-back exhaust system.
- Optimized for both stock engines and vehicles equipped with upgraded turbochargers.
- High-flow design with reduced back pressure.
- Improved throttle response and a broader, more usable powerband.
- Deep, engine-specific sporty exhaust note.
- Reduced sound levels without sacrificing performance.
- JASMA-compliant.
- Direct bolt-on installation with OEM-style fitment.
