Best valved exhaust for BMW M135i F20 / F21

Your vehicle.

All our exhausts for this generation, version by version, are brought together on one page: BMW 1 Series F20 / F21 Valved Exhaust.

A rare combination for a compact: rear-wheel drive and a straight six. That is what makes the M135i N55 so sought after; the Rog exhaust covers it in three-door and five-door form alike.

Body styles

F20 five-door, F21 three-door

Years covered

2013 to 2016

Engine

N55: 3.0-litre single-turbo straight six

Factory output

320 hp, then 326 hp after the facelift, and 450 Nm (235 to 240 kW)

Emissions control

Catalytic converter in the downpipe

Factory valves

Controlled by the drive modes on cars fitted with them

What holds back the factory sound

The N55 climbs through the revs smoothly, with a metallic timbre that is part of its charm; the factory exhaust, designed to stay discreet, lets very little of it through.

What the Rog exhaust changes

With the Rog exhaust and the valves open, the M135i makes itself heard at start-up, climbs through the revs with a raw voice and cracks on the overrun; with the valves closed, it stays an easy-going compact. Power only changes with the downpipe and a remap: here are the published figures.

Factory figures by version; Stage 2 published for the 326 hp version, with a remap.

Closely related versions have their own guide: BMW M2 N55 F87 3.0T, BMW 640i N55 F06 / F12 / F13 3.0T, BMW 535i N55 F10 / F11 3.0T.

Choosing your exhaust.

Five decisions, in this order: each one builds on the one before, and the last no longer affects the sound. Before you start, here is what you are buying.

Your exhaust, in two parts

1. 1

   Step 1 of 5: Sound: the voice of your car

   An exhaust's sound is shaped in three places: its character, which you choose here; its intensity, which depends on the front section (step 3); and the volume of the moment, which you set with the valves (step 4).

   The character

   At the same price, two characters: the straight pipe, to hear the raw sound of the engine, unfiltered; the resonator, for a rounder, slightly softer voice. With either one, the exhaust stays fully sporty.

   

   Pure · straight pipe

   Same price

   

   Round · resonator

   Same price

   Our advice. The straight pipe if you want to hear your engine unfiltered, the resonator if you prefer a rounder voice. Exhaust resonator: what does it do?.

2. 2

   Step 2 of 5: Material: stainless steel or titanium

   The material changes three things: weight, sound and durability. It is a genuine technical choice, not just a matter of looks.

   304 stainless steel

   Base price

   Weight

   Baseline

   Sound

   Full and rounded

   Durability

   Withstands salt and winter

   Tough, corrosion-proof, with a full, rounded sound. The choice of most of our customers.

   Titanium

   Optional

   Weight

   Around 40% lighter

   Sound

   Metallic, crystal-clear

   Durability

   Does not rust

   Around 40% lighter than stainless steel for the same design, with a more metallic sound that turns crystal-clear at high revs. You then choose it in one of three colours, at the same price (step 5).

   Our advice. Stainless steel for a first purchase and everyday use; titanium if you are chasing every kilo and want a higher-pitched note at high revs. Over time, both last. Stainless steel or titanium: what really changes.

3. 3

   Step 3 of 5: Front section: sports catalytic converter or decat

   On your car, the front section is the downpipe, at the turbo outlet: that is where the catalytic converter sits. After the exhaust itself, it is the part that matters most, for sound as well as for breathing. It is optional; on the product page, this option is called “Manifold”: it is the same part, catalytic converter included.

   Cat-back only

   Included

   7/10

   Factory catalytic converter retained

   You keep the factory front section. It already makes it a different car: most of our customers start here.

   200-cell sports catalytic converter

   Optional

   8/10

   Road use and inspection

   Emissions control stays in place, flow improves markedly and the sound gains presence. Our choice for the road.

   100-cell sports catalytic converter

   Optional

   9/10

   Inspection: depends on the vehicle

   Half as many cells: more breathing and more aggression at high revs.

   Decat

   Optional

   10/10

   Track use

   No emissions control: maximum flow and raw sound, for the track.

   Sound intensity, on a scale of 0 to 10

   1. 10/10Decat downpipe + Rog cat-back
   2. 9/10100-cell sports catalytic converter + Rog cat-back
   3. 8/10200-cell sports catalytic converter + Rog cat-back
   4. 7/10Rog cat-back only, factory catalytic converter retained
   5. 3/10Factory exhaust, for comparison

   Valves open. With the valves closed, every configuration becomes discreet again.

   Our advice. Your reference point is a score out of 10: 7 with the exhaust alone, 8 to 9 with the 200-cell sports catalytic converter, 10 with the decat version, for the track. With a remap by a tuner, it is also the front section that unlocks the power (see “Your vehicle”).

   

   What about the engine warning light? With a sports catalytic converter, it can come on with some engines: the sensor placed after the catalytic converter measures a different level of emissions control from the original. It is not a mechanical fault, and a remap by a tuner sorts it out. The decat version almost always triggers it. Passing inspection with a sports exhaust.

4. 4

   Step 4 of 5: Valves: our remote or your factory valves

   The valves set the volume at every moment: closed, the gases pass through the silencer and the car keeps a sound close to the factory one; open, they take the shortest route. All that remains is to choose who controls them.

   Rog system and remote

   Included

   

   The exhaust comes with our valves fitted and a two-button remote, open and closed; a small control unit fits in the boot. The valves stay in the position you choose, whatever the drive mode: open, they stay open; closed, they stay closed.

   Your factory valves

   Included

   • If your car has factory valves
   • Controlled by the drive modes

   If your car has factory valves, we deliver the exhaust with mounting points for them: your garage refits your valves there, and everything works as before, through the drive modes.

   

   Our advice. The remote if you want to decide for yourself, at any time; your factory valves if you value the standard drive modes. For inspection, present the car with the valves closed. On track, open them: that is where they come into their own.

   On the motorway, with the valves closed, the gases pass through the silencer, designed for cruising: no drone at a steady speed. You open up when you feel like it, not when the motorway decides for you. Why our exhausts stay calm on the motorway.

5. 5

   Step 5 of 5: Looks: titanium colour and tips

   The last step, and the freest. The titanium colour and the tips are purely aesthetic choices: they change nothing about the sound or the performance of the exhaust. Choose them with your eyes.

   The titanium colour

   Three colours, at the same price: brushed, gold or purple. They only apply to titanium; in stainless steel, the exhaust keeps the colour of the steel.

   

   

   

   The tips

   Rog tips in chrome, gloss black or blued titanium, included in the price, or carbon tips with the M logo, as an option: forged carbon, black carbon or carbon and titanium. You can also order the exhaust without tips.

   

   

   

   

   

   

Three set-ups, three uses.

If you are still unsure, start from how you use the car: here are the three set-ups we recommend most often for your car.

• Everyday

  • Stainless steel
  • Cat-back only
  • Rog remote

  Your car finds its voice, the factory emissions control stays in place, and you open the valves when you decide.

  View this configuration

• Fast road

  • Titanium
  • 200-cell sports catalytic converter

  More sound and more breathing, with emissions control retained. With a remap, it is the basis of a Stage 2.

  View this configuration

• Track

  • Titanium
  • Decat

  For the track: maximum flow and raw sound. And on track, the valves stay open.

  View this configuration

From order to installation.

1. Configuration

   You choose your exhaust and enter your VIN, found in box E of your registration document.

2. Check

   We check compatibility with your VIN before manufacturing begins.

3. Manufacturing

   Your exhaust is made to order, for your car.

4. Delivery

   Free, insured to your door, tracked from dispatch.

5. Installation

   At your garage, with no welding or cutting: clamps, new gaskets and roughly two hours on a lift.

20 working days from order confirmation to delivery

Warranty

3 years, parts and workmanship, from the date of purchase

Payment

Card, PayPal or bank transfer

Installation

By the garage of your choice

Every exhaust is made to your VIN and checked before production: it fits your car perfectly.

Questions.

Further reading.

• All BMW exhaust systems
• BMW M140i B58 F20 3.0T
• Exhaust resonator: what does it do?
• Downpipe: what is it and what does it do?
• Stage 2: the role of the downpipe
• How to pass vehicle inspection with a modified exhaust
• Exhaust and manufacturer's warranty: what you need to know
• All the brands we cover