IRL MaxFlow Race 400 Cell Downpipes BMW G87 M2 / G80 M3 / G82 M4

Upgrade the restrictive factory downpipes on your S58-powered BMW with the IRL MaxFlow 400-Cell High-Flow Catted Downpipes. Featuring 3-inch tubing and premium 400-cell metallic catalytic converters, the MaxFlow design reduces exhaust backpressure to improve turbocharger efficiency, throttle response, and overall performance while retaining a more refined exhaust character than lower-cell-count or catless downpipes. Improved exhaust flow helps the S58's twin turbochargers spool more quickly and adds a deeper, more aggressive tone without introducing the harshness commonly associated with more extreme downpipe setups. Constructed from T304 stainless steel with precision TIG welds, these downpipes are designed for long-term durability and OEM-style fitment. They're also compatible with the factory exhaust and most aftermarket cat-back systems, making them an excellent first step for a street-oriented performance build or supporting modification for a tuned S58. Fitment Notes Fits BMW G87 M2 (S58) Fits BMW G80 M3 Fits BMW G81 M3 Touring Fits BMW G82 M4 Coupe Fits BMW G83 M4 Convertible Direct bolt-on installation using OEM mounting locations Compatible with the factory exhaust system Compatible with most aftermarket cat-back exhaust systems ECU tuning is not listed as mandatory, but IRL recommends tuning to optimize performance and catalyst efficiency The 400-cell design reduces the likelihood of a catalyst-efficiency CEL compared with lower-cell-count options, but IRL does not guarantee CEL-free operation Not EPA certified; IRL specifies these downpipes for off-road and motorsport use only where permitted by law Included Driver-side IRL MaxFlow catted downpipe Passenger-side IRL MaxFlow catted downpipe Integrated 400-cell metallic catalytic converters Product Specs IRL Part Number: IRL-G8X-400C Downpipe Diameter: 3 inches Catalyst Type: 400-cell high-flow metallic Material: T304 stainless steel Construction: Precision TIG welded Configuration: High-flow catted downpipes Installation: Direct bolt-on Designed for the BMW S58 twin-turbocharged engine Compatible with OEM and most aftermarket exhaust systems Product Features 400-cell metallic catalysts provide a strong balance between increased exhaust flow, improved sound, and a more refined character than lower-cell-count alternatives 3-inch MaxFlow design reduces backpressure and improves exhaust flow from the S58's twin turbochargers Improved flow supports quicker turbo spool, sharper throttle response, and increased horsepower and torque Produces a deeper performance exhaust note without the excessive harshness commonly associated with more aggressive downpipes Premium T304 stainless steel construction and precision TIG welding provide excellent durability in high-temperature turbocharged applications OEM-style mounting and compatibility with factory or aftermarket exhaust systems make installation straightforward and future exhaust upgrades easier