Active Autowerke BMW B58 F3X M240i 340i 440i Catted Downpipe

Active Autowerke BMW B58 Catted Downpipe - now includes turbo flange gasket SHIPPING NOW. Please note that we install the gasket into the downpipe flange as some customers were damaging the gasket on installation.   BMW introduced a new valvetronic, single turbo version of its direct-injection engine for the later F-Chassis models beginning in 2016. The Active Autowerke B58 downpipe for the 340i and 440i helps unleash some of the potential that is restricted by the OEM downpipe. Turbochargers are powered by spent exhaust gases created during the combustion process. The quicker these gases are evacuated, the better. Unfortunately, the factory down pipe in the B58 is quite restrictive, which results in slower exhaust gases and slower turbo spool. The Active Autowerke F-Chassis B58 Signature down pipe utilizes 4.5 diameter stainless steel piping in order to provide more power, quicker spool, and extreme durability. It then tapers down to 3.5" where we've incorporated a stainless flex join