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Configuration
BMW M135i N55 F20 / F21 Valved Exhaust System (2013-2016)
Valves
Operated by remote control, factory-paired.
Estimated at 0.50 m from the outlet, 45°, 2,000 rpm with a warm engine. Allow ± 2 dB depending on the engine and measuring point. A 3 dB difference is audible in a direct comparison; 10 dB sounds roughly twice as loud.
Configuration guide
Sound intensity with the valves open, on a scale of 0 to 10.
| Configuration | Intensity |
|---|---|
| Decat downpipe + Rog cat-back | 10/10 |
| 100-cell sports catalytic converter + Rog cat-back | 9/10 |
| 200-cell sports catalytic converter + Rog cat-back | 8/10 |
| Rog cat-back only, factory catalytic converter retained | 7/10 |
| Factory exhaust, for comparison | 3/10 |
Which valved exhaust for a BMW M135i N55 F20 / F21?
The Rog system for the BMW M135i N55 is a valved cat-back exhaust for the five-door F20 and three-door F21, built to your VIN in 304 stainless steel or titanium for the 320 to 326 hp turbo six-cylinder. Valves open, the N55 regains its metallic harmonics and a raspy climb through the revs; closed, the M135i stays an easy-going compact.
Sound, options and fitting in detail: our BMW M135i N55 guide.
Compact, rear-wheel drive and an inline-six: the M135i with the N55 engine brought together a combination no rival offered. Its 3.0-litre with a single twin-scroll turbo is rated at 320 hp and 450 Nm, then 326 hp after the facelift, for the 2013 to 2016 model years. Enthusiasts actively seek it out today, often to keep it for a long time.
Deeper and more mechanical than recent six-cylinders, the N55 revs in a linear way with very endearing metallic harmonics, precisely what the factory system, sized for discretion, holds back. The Rog valved cat-back gives it an assertive presence from idle, a gruff climb through the revs and frank crackles on the overrun when the valves are open. Closed, they leave you with a perfectly liveable compact.
Fitting requires neither welding nor cutting, just band clamps, gaskets and about two hours on a lift, as the system is built to your VIN. If your M135i has factory valves, their control is retained; otherwise, the two-button Rog remote works whatever the driving mode; for the four-cylinder M135i F40 or the M140i B58, see their respective pages.
On this single-turbo, the front part sold under the “Manifold” option is the downpipe, and it is an ECU remap that converts it into power; on its own, it changes sound and weight. Three variants exist for this single-turbo downpipe: 200-cell catalysed, which preserves the emissions control of an everyday hatchback, 100-cell catalysed, accepted or not depending on the car and the rules in your country, and decat, a version reserved for track use. Many M135i owners choose 304 stainless steel for the N55’s deep tone, others titanium, around 40% lighter and finished in brushed, gold or purple.
BMW M135i N55 F20 / F21 3.0T exhaust specifications.
| System type | Valved cat-back (valve exhaust), built to your VIN |
|---|---|
| Vehicles and chassis codes | BMW M135i N55, F20 five-door and F21 three-door |
| Engine | N55, 3.0-litre turbocharged inline-six, 320 to 326 hp and 450 Nm |
| Power in kW | 235 to 240 kW |
| Years | 2013-2016 |
| Materials and finishes | 304 stainless steel or titanium; titanium in brushed, gold or purple |
| Valves | Factory valve control if the car has it, otherwise the Rog remote |
| Front section (option) | Downpipe with 200-cell or 100-cell catalytic converter, or decat |
| Fitting | No welding or cutting, about 2 hours |
| Manufacturing and delivery | Made to order, 20 working days, free delivery |
| Warranty | 3 years, parts and workmanship |
Questions about the BMW M135i N55 F20 / F21 3.0T exhaust.
Can a 2012 M135i or a three-door benefit from this exhaust?
Yes for the three-door: the F20 five-door and the F21 three-door take the same Rog system, with the same N55 and the same clamp-and-gasket fitting. For a 2012 M135i, before the years covered by this page, send us the VIN: we check the model year before manufacturing.
What figures can an M135i N55 aim for at Stage 2?
With a downpipe and a remap at an approved tuner, the page quotes 410 hp and 600 Nm for the 320 hp version, and 399 hp and 546 Nm for the 326 hp facelift; the cat-back, for its part, is happy with the factory map.
On vehicle inspection day, what should you do with your six-cylinder M135i?
Drive to the centre with the valves closed: the compact arrives with a voice close to standard, and its gas treatment remains complete as long as the front section is the factory one or the 200-cell downpipe, whereas the 100-cell is accepted or not depending on the vehicle and your country’s rules and the decat version is reserved for track use.
On the motorway, will the M135i resonate in the cabin?
No, as long as the valves stay closed, the gases pass through the cruising silencer and the compact keeps a serene cabin at a steady speed; you only open up when the road allows.
Which material should you choose for an M135i’s N55?
304 stainless steel emphasises the inline-six’s deep tone and weathers the seasons without complaint; titanium, around 40% lighter for the same design, brightens the note at high revs and comes in three colours.
BMW M135i N55 F20 / F21 3.0T: Does a valved exhaust system drone?
No. With the valves closed, the gases flow through the whole rear silencer and the cabin stays calm at a steady speed. Our Rog exhausts are designed to avoid drone. Learn more: Why our systems stay calm on the motorway.
BMW M135i N55 F20 / F21 3.0T: straight pipe or resonator?
On this model, two characters at the same price: the straight pipe for the raw sound of your engine, unfiltered, or the resonator for a rounder and slightly softer voice. Either way, the exhaust stays fully sporty. Learn more: Exhaust resonator: what does it do? Straight pipe or resonator, which sound to choose.
Rog expert guide
Best valved exhaust for BMW M135i F20 / F21
For a BMW M135i F20 or F21, the best valved exhaust is the one made to your VIN, with a sound you choose, to give the six-cylinder back its full voice. That is what the Rog exhaust offers: a cat-back...
In detail
Rog Advisor
A question about this exhaust?
Fitment, sound, catalyst, valves, delivery: the answer comes straight away, with your configuration in context.
The Rog Advisor is an automated assistant trained on our product pages and answers. For an important decision, write to us: we confirm by e-mail.
Unsure about your configuration? Talk to us before you order. We know your car. Write to us at contact@rogmotorsport.com: we reply in writing, in English, within 24 hours. Email us
Reviews imported from our previous system and translated from French; verified purchases carry the badge.
Rog presentation film: choosing your vehicle, Standard or Equal Length design, stainless steel or titanium, Z-Pipe, controlled valves, titanium and tip finishes, and support from choosing your configuration through to shipping.
THE Rog CRAFT
Our process.
From the first bend to the last check. The same care at every step.
-
Design
Designed for your vehicle.
Geometry matched to your model, carefully studied bends and precise mounting points. Everything starts with accurate design.
-
Manufacture
Crafted with precision.
Tube bending, part fitting and TIG welding: every joint receives the same care.
-
Finishing
Material, elevated.
The finish reveals the character of the metal. Stainless steel or titanium, depending on the options available for your vehicle.
-
Assembly
Every part in its place.
Components are assembled and adjusted. On valved systems, the mechanism is fitted, set up and tested.
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Inspection
Check. Then approve.
Geometry, welds, connections and gas flow: the key points are inspected before shipping.
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Shipping
Ready to join you.
Reinforced packaging protects your exhaust in transit. The final step before giving your vehicle a new voice.
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