304 Stainless Steel Exhaust System

The AR Design 3" High Flow Cat Downpipes are designed for the BMW 135i, 335i, and 335xi with the N55 engine, model years 2011 and up. These are the only true 3" catted downpipes on the market, maintaining a 3" diameter until the cat-back flange, unlike systems that reduce to 2.5" closer to the turbo. Constructed from premium 304 Stainless Steel (with 409 Stainless for the cats), these downpipes are 100% hand TIG welded in the USA with argon backpurging for optimal penetration and strength. They feature water-jet cut 304 Stainless cat-back flanges and CNC'd 304 Stainless V-Band flanges, along with Magnaflow 3" metal substrate race cats. Included with the downpipes are a set of exclusive "bomb-proof" exhaust gaskets and Grade 10.9 Metric Hardware, which boasts 145,000 PSI tensile strength. Nord-Lock positive locking, reusable washers are also provided. The O2 bungs are positioned at the factory location. While these downpipes offer an intoxicating sound and significant power gains, virtually eliminating turbo lag, it is important to note their intended use. Many items are intended for off-road use and purpose-built race cars only. Claims as to emission performance for street or highway use are not made, and they are not sold for street use in states or countries where regulations prohibit it. No emissions-related equipment is shipped to California, and an off-road/track use only waiver is required before shipping. Additionally, while these downpipes provide NO CEL (Check Engine Light) on pre-29.2 cars, post-29.2 cars may require a DP Fix. A lifetime warranty against manufacturing defects is provided to the original owner, and an optional 2000°F ceramic coating is available, offering a 3-year warranty against corrosion and rust.