BMW 435i Front Downpipes Sports Cat / Decat Version N55 Engines

The ASM Performance exhaust sections for the N55 engines are meticulously engineered to improve your vehicle sound, delivering the ultimate driving experience.

Our downpipes come equipped with a heat shield to contain heat and unleash the full power of your car during high-speed accelerations.

Constructed from high-grade stainless steel and wrapped in thermal protection, this downpipe ensures long-term durability under extreme heat. Whether you’re building a street car or prepping for the track, it’s the ultimate bolt-on exhaust mod for more power and sound.

Our sports exhaust selection is fully backed with a lifetime warranty, ensuring quality assurance.

Features & Details

• Substantial power increase
• Specially designed smooth transition for optimized flow
• Improved spool up speed and throttle response
• Extended turbo lifespan
• Lowering under hood temperature
• Enhanced performance sound
• 100% Easy and secure bolt-on installation
• Fully tig welded and back purged crafting
• Top-tier 304L stainless steel with a 2.00mm thick wall
• Compliant with both LHD and RHD vehicles
• Backed by a lifetime warranty

These will fit the following models:

• 1 Series (F20) M135i, M135i XDrive 235 kW + 240 kW N55 engine, built from 07/2013
• 1 Series (F21) M135i, M135i XDrive, 235 kW N55 engine, built from 07/2013
• 2 Series (F22) M235i, Coupe, 240 kW N55 engine, built from 07/2013
• 2 Series (F23) M235i, Cabriolet, 240 kW N55 engine, built from 07/2013
• 2 Series (F87) M2, 272 kW N55 engine, built from 07/2013
• 3 Series (F30) 335i, 335iX, Sedan, 225 kW + 240 kW + 250 kW N55 engine, built from 07/2013
• 3 Series (F31) 335i, 335iX Touring, 225 kW + 240 kW + 250 kW N55 engine, built from 07/2013
• 3 Series GT (F34) 335i, 335iX, Gran Turismo, 225 kW + 240 kW + 250 kW N55 engine, built from 07/2013
• 4 Series (F32) 435i, 435iX Coupe, 225 kW + 250 kW N55 engine, built from 07/2013
• 4 Series (F33) 435i, 435iX, Cabriolet, 225 kW + 250 kW N55 engine, built from 07/2013
• 4 Series (F36) 435i, 435iX Gran Coupe, 225 kW + 250 kW N55 engine, built from 07/2013

Sport Cat Downpipes

Catalytic Converter Included: Sport cat downpipes include a high-flow catalytic converter. This helps reduce exhaust emissions while still allowing for increased flow compared to standard catalytic converters.

Emissions Compliance: They are designed to be street-legal in many areas, as they still filter harmful emission, though regulations can vary by region.

Performance: Sport cat downpipes strike a balance between performance and emissions compliance. They offer a noticeable increase in horsepower and torque compared to stock downpipes, but might not be as free-flowing as decat downpipes.

Sound: The sport cat downpipes provide a moderate increase in exhaust sound over the stock system.

Decat Downpipes

No Catalytic Converter: Decat downpipes eliminate the catalytic converter entirely, resulting in zero filtration of exhaust gases. 

Higher Performance: They allow for maximum exhaust flow, which can result in significant performance gains, particularly for turbocharged engines.

Emissions Non-Compliance: Decat downpipes are typically illegally for street use in most regions due to their complete lack of emissions control. They are generally indented for track use or off-road racing.

Emissions Non-Compliance: They produce a louder and more aggressive exhaust note.

The de-cat exhaust version is available for motorsport and off-road use exclusively worldwide.

The downpipe is the first section of the exhaust after the turbocharger, so it has a direct effect on how freely the engine can breathe. The ASM stainless steel downpipe for the BMW 4 Series F32 / F33 / F36 / 4 Series F32 / F33 / F36 is built for stronger exhaust flow, sharper throttle response and a fuller sound, and is usually paired with an ECU remap.

Stainless steel is used because it resists corrosion and copes with the heat cycles of a turbocharged engine.

Fitting a downpipe should be done by a qualified technician, and most cars need an ECU remap afterwards so the engine runs correctly. Use new gaskets and check for leaks once the system is warm. Step-by-step advice: Downpipes explained: sports cat vs de-cat.

Sports cat and de-cat downpipes change the emissions system, so road use rules differ by country. Check the rules where you drive before fitting – see are downpipes road legal in the UK?

Every order ships from the UK with tracked delivery to the UK, Europe and worldwide. Delivery options and costs are shown at checkout and explained in our shipping policy. Unused items in original condition can be returned within 14 days, and return shipping is paid by ASM – see the refund policy. Manufacturing defects are covered by the ASM warranty.

Which cars does this downpipe fit?

It is made for the BMW 4 Series F32 / F33 / F36 / 4 Series F32 / F33 / F36. Fitment depends on the exact model, bumper and specification, so if your car has a facelift (LCI) bumper, a different trim level or other aftermarket parts, contact us with your VIN or a photo and we will confirm fitment before you order.

What is the downpipe made from?

It is made from stainless steel, which resists corrosion and copes with the high exhaust temperatures of a turbocharged engine.

Do you ship to my country?

Yes. We ship from the UK to the UK, Europe and worldwide with tracked delivery. Prices can be shown approximately in EUR or USD, and orders are charged in GBP.

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