Unlock the True Potential of Your N55
Transform your BMW's performance and soundtrack with the Flashark High-Flow Downpipe. Specifically engineered for the early F-chassis N55 engine, this upgrade removes the primary bottleneck in your exhaust system, allowing your turbo to breathe, spool faster, and deliver massive power gains.
Engineered for Quality
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100% Bolt-On Installation: No cutting, welding, or permanent modification required. All factory O2 sensor bungs are retained in their original positions.
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Maximum Flow: The smooth mandrel-bent tubing ensures zero internal restrictions, unlike the crimped factory piping.
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Complete Hardware Kit: Every downpipe comes with the necessary gaskets and high-strength bolts to ensure a leak-free seal from day one.
Features
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Precision 3.5" Fitment: Designed exclusively for N55 models produced between 2012 and July 2013. (Please verify your turbo outlet size is 3.5" before ordering).
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Significant Power Gains: Expect an increase of 15-25 HP and 20+ lb-ft of torque when paired with a Stage 2 tune.
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Faster Turbo Spool: Mandrel-bent piping reduces backpressure, significantly cutting down turbo lag for instant throttle response.
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T304 Stainless Steel: Built to last with heavy-duty, corrosion-resistant stainless steel and precision TIG-welded seams.
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Aggressive Sound: Gives your N55 a deep, throaty growl under acceleration while maintaining civility during daily cruising.
Pro Tip for BMW Owners:
To get the most out of this hardware and avoid a "Check Engine Light" (CEL), we highly recommend a Stage 2 ECU Flash (like Bootmod3 or MHD). This will calibrate your engine for the increased airflow and maximize your Horsepower gains!
What’s in the Box?
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(1) 3.5" N55 High-Flow Downpipe
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(1) High-Temperature Flange Gasket
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(1) Set of Heavy-Duty Mounting Bolts
Fitment & Compatibility
IMPORTANT: This downpipe features the 3.5-inch (90mm) flange. BMW switched to a 4-inch flange after 07/2013.
| Model | Chassis | Year Range | Engine Spec |
|---|---|---|---|
| BMW 135i / M135i | F20 / F21 | 2012 - 07/2013 | N55 (3.5" Flange) |
| BMW 335i / 335i GT | F30 / F34 | 2012 - 07/2013 | N55 (3.5" Flange) |
| BMW 435i | F32 / F33 / F36 | 2012 - 07/2013 | N55 (3.5" Flange) |
| BMW M2 | F87 | 2014 - 07/2013 | N55 (3.5" Flange) |
Flashark 3.5" N55 Downpipe Upgrade FAQ
Q1: What are the main benefits of upgrading to a Flashark high-flow N55 Downpipe?
A1: The factory downpipe is highly restrictive, creating backpressure that chokes your turbo. Upgrading to our high-flow N55 downpipe significantly reduces this restriction, resulting in massive horsepower and torque gains (15-25 HP), significantly faster turbo spool, and a much more aggressive exhaust note.
Q2: How do I know if I need the 3.5" or 4" N55 downpipe for my engine?
A2: This is the most crucial step! BMW used a 3.5-inch v-band flange for N55 engines with a Pneumatic Wastegate (PWG) built from 2012 up to July 2013. If your car was manufactured after 08/2013, it likely has an Electronic Wastegate (EWG) and requires a 4-inch downpipe. Always check your driver's side door jamb for the exact production month and year before ordering.
Q3: Which BMW F-chassis platforms is this specific N55 downpipe compatible with?
A3: This specific 3.5" upgrade is precision-engineered exclusively for the early F-chassis architecture. It perfectly fits the F20 and F21 (1 Series), F22 (2 Series), F30 and F34 (3 Series), F32, F33, and F36 (4 Series), as well as the early F87 platform, provided they fall within the correct production date range.
Q4: Does this N55 downpipe fit all early F-Series car models?
A4: It fits the flagship N55-powered models produced between 2012 and 07/2013. This includes the M135i, M235i, 335i, 435i, and select early productions of the M2. It does not fit 4-cylinder models (like the 328i) or later B58-powered vehicles.
Q5: I drive a 2013 BMW 335i. Will installing this downpipe trigger a Check Engine Light (CEL)?
A5: Yes, replacing the restrictive factory catalytic converter on your 335i with a high-flow or catless N55 downpipe will typically trigger a CEL due to the increased exhaust flow altering O2 sensor readings. To clear the light and safely maximize your horsepower gains, we highly recommend pairing this hardware with a Stage 2 ECU tune (such as MHD or Bootmod3).
Q6: Do I absolutely need to tune my car after installing this N55 downpipe?
A6: While the car will run without a tune and you will still experience faster turbo response and a better sound, a Stage 2 tune is highly recommended. The tune calibrates your engine parameters to take full advantage of the increased airflow, unlocking the true performance potential and keeping your dashboard clear of warning lights.
Q7: Will this N55 downpipe change my exhaust sound?
A7: Absolutely. Removing the heavy factory catalyst allows the true sound of the inline-6 engine to escape. You can expect a significantly deeper, throatier growl under heavy acceleration, noticeable turbo spooling/whistling sounds, and more pronounced exhaust burbles, while remaining civilized during regular daily driving.
Q8: Is the installation of this N55 downpipe a direct bolt-on?
A8: Yes! We designed this as a 100% direct bolt-on replacement. There is no cutting, welding, or custom fabrication required. It utilizes the factory mounting points and retains the original O2 sensor bungs in their correct locations for a straightforward installation.
Q9: Why does Flashark use T304 stainless steel for this N55 downpipe?
A9: Downpipes are subjected to extreme Exhaust Gas Temperatures (EGTs) right off the turbo. T304 stainless steel offers superior heat resistance and exceptional corrosion protection compared to cheaper materials or factory piping. Combined with our precision TIG welding, it ensures your downpipe won't crack or rust, delivering a lifetime of performance.
Q10: What hardware is included with the N55 downpipe purchase?
A10: We provide everything you need for a leak-free installation. Each box includes the 3.5" N55 downpipe itself, a high-temperature flange gasket, and a set of heavy-duty mounting bolts. (Note: We recommend re-using your factory v-band clamp at the turbo housing if it is in good condition).