Product Specifications
BMW N55 4-Inch Catless Downpipe for 335i, 435i, M135i, M235i & M2
A freer exhaust path gives the turbocharged N55 a more direct exhaust character and lets the turbo discharge gases move through a less restrictive section. This Flashark 4-inch catless downpipe is made for the listed BMW 335i, 435i, M135i, M235i and N55-powered M2 applications.
The stainless-steel pipe uses mandrel-bent tubing, TIG-welded joints and a CNC-machined turbocharger V-band flange. It replaces the factory catalytic downpipe section and connects to the factory exhaust or a compatible aftermarket exhaust configuration.
Specifications
| Product Type | Catless turbo downpipe |
|---|---|
| Nominal Pipe Size | 4 inches |
| Material | Stainless steel |
| Tube Forming | Mandrel-bent tubing |
| Welding | TIG-welded joints |
| Turbo Connection | CNC-machined V-band flange |
| Catalytic Converter | Not included; catless configuration |
| Engine Application | BMW N55 3.0L turbocharged inline-six |
| Product SKU | FLES08194 |
Key Features
- 4-inch catless layout: Replaces the restrictive factory catalytic downpipe section with a freer-flowing exhaust path after the turbocharger.
- N55-specific connection: Uses a CNC-machined V-band flange at the turbocharger connection.
- Stainless-steel construction: Mandrel-bent tubing and TIG-welded joints provide a durable exhaust path.
- More assertive exhaust character: Removing the factory catalytic section produces a louder and more direct exhaust note.
- Factory or aftermarket exhaust use: Designed to connect with the factory exhaust or a compatible downstream exhaust configuration.
- Clear application boundaries: Intended only for the listed BMW N55 applications.
Need a Downpipe for a 2011–2012 E-Series N55?
For a 2011–2012 BMW 135i or 335i with an E82, E88, E90 or E92 chassis, view the N55 catless downpipe for E-series BMW 135i and 335i. Match the chassis, engine and model year before ordering.
Built for Better Exhaust Flow and Sound
The factory catalytic section creates resistance immediately after the turbocharger. Replacing that section with a catless downpipe helps exhaust gases leave the turbo more freely. Turbo response may feel sharper, while the final result depends on the vehicle’s calibration, engine condition and complete intake and exhaust configuration.
Expect a louder cold start, a more noticeable turbo and exhaust note under load, and a stronger exhaust smell than the factory catted system. Rasp and cabin drone depend heavily on the remaining exhaust components. Muffler deletes, resonator deletes and straight-through exhaust systems can make the overall setup considerably louder.
Factory Downpipe vs. Flashark Catless Downpipe
| Feature | Factory Downpipe | Flashark Catless Downpipe |
|---|---|---|
| Catalytic converter | Factory catalytic section retained | No catalytic converter |
| Exhaust restriction | Designed around factory emissions and sound targets | Freer exhaust path after the turbocharger |
| Sound | Quieter factory exhaust character | Louder, more direct turbo and exhaust note |
| Exhaust odor | Catalytic converter helps control exhaust odor | Stronger exhaust odor can be noticeable |
| Warning-light risk | Factory emissions monitoring retained | An emissions-related CEL may occur |
Installation Notes
- Allow the exhaust system and turbo area to cool fully before beginning work.
- Protect the oxygen sensors and wiring from twisting, impact and excessive heat during removal and installation.
- Inspect sealing surfaces and connections before assembly.
- Start the engine after installation and inspect every connection for an exhaust leak.
- Existing exhaust modifications can change alignment, clearance and installation time.
- Professional installation is recommended when turbo-side exhaust work or oxygen-sensor removal is unfamiliar.
Who This Downpipe Is For
This catless N55 downpipe is intended for owners building a performance-focused BMW who want a freer exhaust path and a more aggressive exhaust note. It is best suited to off-road or closed-course vehicles where the owner accepts additional sound, exhaust odor, CEL risk and emissions restrictions.
A catted downpipe or factory replacement is the better choice for drivers who need emissions compliance, minimal exhaust odor, factory-like sound or the lowest possible warning-light risk.
Emissions and Street-Use Notice
This product removes the factory catalytic converter. It may not be legal for use on public roads where catalytic converters or factory emissions equipment are required. It can also prevent the vehicle from passing an emissions or OBD inspection. Check the laws and inspection requirements that apply to the vehicle before purchase or installation.
