Pro Circuit TI-4 GP Exhaust System This full race system is designed to increase performance from bottom to top end, making it easier to ride faster. Full Titanium construction offers an incredible weight savings when compared to the OEM system. If noise is an issue don't worry, the Ti-4 exhaust complies with all the new AMA sound restrictions. The ultra-lightweight titanium Ti-4GP is Pro Circuit's premium exhaust system and it includes a titanium header pipe. The silencer can is easily repacked simply by removing the inlet cap screws and re-wrapping the silencer core |