BMW 1 Series F20 F21 M135i 12-16 3" Valved Catback Exhaust System

Direnza cat back exhaust systems are manufactured from T304 grade brushed stainless steel, perfect for those intense track-sessions. A direct replacement for the stock part, Direnza mandrel-bent exhaust components are fully TIG welded and feature CNC-machined flanges for strength and an accurate, secure fit every time. Engineered to not only improve power and torque across the entire RPM range but Direnza exhaust components improve throttle response to help you push further and faster on the road or the track Manufactured from highest quality T304 grade stainless steel CNC machined flanges for strong, solid support and an accurate fit 3" Bore for maximum gas flow which gives instant performance gains along with enough bore for more power in the future Built in valve so the desired volume is in your hands ​We recommend all exhaust components are fitted by a qualified mechanic to ensure the correct fitment Dyno Testing: Stock: 296.2hp 487.1nm Exhaust: 315.1hp 489.4nm (+18.9hp +2.3nm)