The IRL MaxFlow 400 Cell High-Flow Downpipes are engineered for enthusiasts looking to maximize the performance of their S58-powered BMW while maintaining a refined exhaust tone. Featuring premium 400-cell high-flow metallic catalytic converters, these downpipes provide significantly improved exhaust flow over the factory units, helping reduce backpressure, improve turbocharger efficiency, and deliver noticeable gains in horsepower, torque, and throttle response. The IRL MaxFlow design promotes smooth exhaust flow to minimize turbulence and optimize performance throughout the entire RPM range. The result is quicker turbo spool, enhanced throttle response, and a deeper, more refined exhaust note without the harshness commonly associated with lower-cell-count catalytic converters. Manufactured from premium T304 stainless steel and precision TIG welded, every set is built for exceptional durability and long-term reliability. Designed using OEM mounting locations, these downpipes provide a direct bolt-on installation and are compatible with both the factory exhaust system and most aftermarket cat-back exhausts. Features IRL MaxFlow high-flow design Premium 400-cell high-flow metallic catalytic converters T304 stainless steel construction Precision TIG welded for maximum strength and durability Increased horsepower and torque Improved turbo spool and throttle response Reduced exhaust backpressure Refined performance exhaust tone Direct bolt-on installation OEM-style fitment Compatible with OEM and most aftermarket exhaust systems Vehicle Fitment BMW G87 M2 (S58) BMW G80 M3 BMW G81 M3 Touring BMW G82 M4 Coupe BMW G83 M4 Convertible Important Information: These 400-cell downpipes are not EPA certified and are intended for off-road and motorsport use only where permitted by law. While the 400-cell catalyst design significantly reduces the likelihood of a check engine light compared to lower-cell-count options, IRL does not offer a no check engine light (CEL) guarantee with these units. A CEL may still occur depending on vehicle software, fuel quality, driving conditions, and manufacturing tolerances. ECU tuning may be recommended to optimize performance and catalyst efficiency. It is a violation of Federal and Illinois State laws to use this product in a manner inconsistent with it’s labeling. Our products are "Legal Only For Racing Vehicles Which May Never Be Used, Or Registered or Licensed For Use, Upon A Highway." These products are designed for off road purposes only It is NOT designed or intended to be used in any way that may violate any laws. IRL LLC will not be responsible for the use of Merchandise.
