We are proud to introduce our VRSF catless & catted downpipe for your N55 BMW. This downpipe is THE best bang for the buck mod available. This downpipe is available in both catless (race) & catted configuration. Back pressure is significantly reduced by eliminating the restrictive catalytic converter in the factory downpipe with our catless or high flow 200 cell race cat which results in faster spool, an increase in power & a more aggressive exhaust note. VRSF downpipes are hand crafted from mandrel bent SS304 grade stainless steel and our CNC precision machined flanges are also constructed from billet 304 grade stainless steel. All VRSF products include a lifetime warranty as well as our “No Hassle” satisfaction guarantee (including fitment). All M135i & 335i models produced up to 07/13 require the 3.5″ version of this downpipe. M135 and 335i models produced after 07/13 require the 4″ model of this downpipe. All M235 and 435i models require the 4″ version of this downpipe. Please confirm by looking at your Turbo Wastegate. It is located on the lower passenger side of the engine next to the Turbo. See picture below for reference. Note: We also offer ceramic coating services utilizing Cerakote High Temperature Ceramic coating, made to withstand temperatures up to 1800F. We use Cerakote’s best thermal barrier coating which helps keep the hot air inside the exhaust and out of the engine bay which decreases overall intake air temps along with engine and transmission oil temps. Please note that while we do offer a lifetime warranty on the downpipes, we only offer a 1 year warranty on the ceramic coating as well as the catted versions. VRSF Catless & Catted 3.5″ / 4.0″ N55 Stainless Steel Down Pipe Made from hand crafted, tig welded 304 grade stainless steel. Smooth radius bends to decrease turbulence and increase flow. 200 cell high flow cat as well as catless options available. CNC SS304 stainless steel flanges. Gains from 20-25hp with tune. VRSF Lifetime Warranty This item fits the following BMWs: 2012 – 2018 F30 BMW 335i & 335xi N55 2013 – 2018 F32/F33/F36 BMW 435i & 435xi N55 2012 – 2018 F20/F21 BMW M135i & M135xi N55 2013 – 2018 F22/F23 BMW M235i & M235xi N55 2015 – 2019 F87 BMW M2 N55