Home Makes BMW N55

BMW N55 Exhaust and Downpipe (135i, M135i, M235i, M2, 335i, 435i, 535i, X4 M40i)

Valved exhaust systems and downpipes for the N55 straight six, from the M135i to the M2 F87 and the X3, X4, X5 and X6. Made to order from your VIN, with free delivery.

BMW N55

The N55 at a glance.

The N55 is the 3.0-litre turbocharged straight six that took over from the N54 in 2009, first in the 535i Gran Turismo, before going on to power almost the entire BMW range until the B58 arrived. It displaces 2,979 cc and replaces the two turbos of the N54 with a single twin-scroll turbo, combined with Valvetronic variable valve lift and direct injection. The result: strong pull from low revs and a simpler engine, a firm favourite with tuners.

Depending on the model, BMW quotes 306 hp and 400 Nm for most versions (135i, 335i, 435i, 535i, X3, X4, X5 and X6 35i), 320 hp and 450 Nm for the M135i and 640i, 326 hp for the M235i, 360 hp for the X4 M40i, and 370 hp and 465 Nm (500 Nm on overboost) for the 2016 M2 F87.

Models covered.

Rog makes a system for each of these N55 versions:

Each model also has its own page, with all its versions: for example the 3 Series F30 / F31, the 1 Series F20 / F21 or the M2 F87.

The sound of the N55.

The N55 has the voice of a true straight six, smooth and tuneful, but the standard exhaust holds it back with large silencers. With the valves closed, a Rog system stays close to standard and the cabin stays quiet on the motorway. With the valves open, the engine gains volume and texture: deep at low revs, raspier in the mid-range, far more present towards the top of the rev counter, with the whoosh of the turbo easier to hear.

What the Rog system changes.

The Rog system replaces everything after the catalytic converter, right up to the tailpipes (the cat-back):

  • Adjustable sound: valves closed for everyday driving and long journeys, open when you want to hear it. The system takes your original valves or comes with the Rog valve system and its remote control.
  • Two materials: 304 stainless steel, or titanium, around 40 % lighter for the same design, in a brushed, gold or purple finish.
  • The character of the sound: straight pipe, or resonator for a rounder, slightly softer voice that is just as sporty.
  • The original ECU: on an N55, the cat-back alone needs no remap.

What the downpipe changes.

On the N55, the downpipe is the pipe that leaves the turbo and carries the original catalytic converter. It is the part that restricts the exhaust gases the most: replacing it makes the engine more present and the turbo more audible, and it is what opens the way to power gains, with a remap. Without a remap, it brings sound and less weight, not extra horsepower.

Rog offers it in three versions: 200-cell sports catalytic converter, 100-cell sports catalytic converter, or decat. The 200-cell version keeps emissions control; the 100-cell and decat versions do not. You can order it with the system, in the configuration on your product page, or on its own when it appears in the list on this page.

Made for your car.

Every Rog system and downpipe is made to order from your car's VIN: the N55 was fitted to many body styles, sometimes alongside the N54 in the same model, and the VIN confirms the engine and compatibility before production. Allow 20 working days from confirmation to delivery, with free delivery and a 3-year warranty on parts and workmanship. Fitting is done at the workshop of your choice. We have been producing for more than 15 years.

Sound, options and fitting in detail: our BMW 335i F30 / F31 guide.

Frequently asked questions.

Which cars have the N55 engine?

Among the models Rog covers: 135i E82 / E88 (depending on the year), M135i, M235i, M2 F87 from 2016 to 2018, 335i E90 / E92 / E93 from 2010, 335i F30 and GT F34, 435i, 535i F10, 640i, X3 F25, X4 F26 and X4 M40i, X5 35i F15 and X6 35i F16. Your VIN, given when you order, confirms the engine.

N55 or N54: how can I tell?

The older N54 has two turbos; the N55 has just one, a twin-scroll unit. On the 335i E90 / E92 / E93, the N55 replaced the N54 in 2010; on the 135i E82 / E88, both exist, and our product page covers both. The VIN settles it.

Does an N55 need a remap after an exhaust or a downpipe?

Not for the cat-back alone: the engine keeps its original ECU. With the downpipe, a remap is recommended: it is what unlocks the power, and it stops a sports catalytic converter from triggering the engine warning light.

200-cell, 100-cell or decat: which should I choose?

The 200-cell version keeps emissions control and already gives a more present sound. The 100-cell version lets the gases flow more freely. The decat version is the freest flowing and the loudest of the three.

Is the sound still easy to live with every day?

Yes. With the valves closed, the sound stays close to standard, with no drone at a steady cruise. You open the valves whenever you decide.

Your model is not in this list? Write to us