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 M240i, 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 joint and then down to 80mm to meet the OEM exhaust system. We never drop the diameter to smaller than the stock diameter of 80mm.
The speed of a turbo’s impeller wheel is limited by exhaust back pressure. A larger down pipe relieves some of this pressure, resulting in quicker and more efficient spool. With Active Autowerke’s Signature downpipe, your B58 can rev quicker, and deliver more horsepower and torque.
Minimizing back pressure while retaining daily drive-ability was the goal of our B58 downpipe. Owners can now upgrade to a product that is affordable, reliable, and easy to install. Note: Because this down pipe modifies the factory emissions system it is designed for off-road or racing use only.
After months of research and development, our engineers settled on a 4.5” diameter pipe which utilizes the least number of bends possible. The large volume helps the turbo spool as quickly as possible by eliminating back pressure during spool up.
Constructed entirely from 304 stainless steel with 1.5MM wall thickness, we are confident that you’ll be pleased with how robust and durable this down pipe is. Trouble-free installation and a long lifespan ensure that you’ll enjoy many miles of performance with your B58!
**This product is a part of the Active Autowerke Motorsport Collection. It is for RACE and OFF-ROAD USE ONLY!