Agtronic Motorsport BMW N55 (2011 135i, 335i) high flow downpipe.
Replaces restrictive factory downpipe for a power gain of ~15 hp and ~15 ft/lbs of torque.*
Hand-crafted of T304 stainless steel using CNC machined T303 SS flanges and is fully TIG welded. Features typical Agtronic Motorsport quality all around.
This is the only downpipe for the N55 to feature a high-quality flex bellow. (As BMW engineers intended). This ensure years of abuse with no fear of cracking.
Standard is a built-in "j-bung" to keep the stock ECU happy. This reduces the amount of exhaust gas that comes into direct contact with the secondary O2 sensor, "tricking" the ECU into thinking the catalytic converter is still present and doing its job. So no check engine light! **
As a bonus, you get a great sporty tone out of a stock exhaust.
* Gains are based on a 100% stock car. Expect a good amount more power with a software upgrade and other mods.
** As with every other N55 downpipe, it is for off-road use only.