Boost Logic R35 4″ Titanium Exhaust – Valved Section Upgrade (Muffler section only—requires re-use of your existing tips.) Elevate your GTR’s performance and versatility with our boost-activated valved muffler upgrade. This innovative system keeps the exhaust valves closed below 7 psi of boost, ensuring a quieter, more refined sound during cruising and idling. Once you exceed 7 psi, the valves open seamlessly, unleashing maximum airflow and enabling your engine to deliver peak performance. Designed with precision, this upgrade eliminates any risk of excessive back pressure or power loss when the valves are closed. When opened, the system achieves flow levels comparable to our race-proven standard titanium exhaust, ensuring unparalleled performance and sound. Specifically designed for our Boost Logic 4″ exhaust systems only.