BMW 640i F1x: waking up the N55, the complete exhaust system guide
The 640i, whether coupé, convertible or Gran Coupé, is today a GT with unbeatable value for money. Its single-turbo N55 is smooth, robust and underrated. Built for hushed cruising, the factory exhaust tells you nothing. Our valved exhaust system gives it the dual personality a GT should always have. Here, point by point, is how to choose the exhaust for your BMW 640i N55 F06 Gran Coupé, and what each option really changes.
Written by RogMotorsport · Updated
Your ROG exhaust for BMW 640i N55 F06 Gran Coupé
From €2,190 in stainless steel, €2,690 in titanium
Configure my exhaust- Vehicles
- BMW 640i N55 F06 Gran Coupé 3.0T (2012-2017)
- Engine
- N55 · 320 hp · 450 Nm
- Exhaust
- Valved cat-back, built for your VIN
- Material
- 304 stainless steel or titanium
- Front section
- Optional: catted downpipe with 200 or 100 cells, or decat
- Valves
- ROG remote, or factory control if your vehicle has it
- Lead time
- 20 working days from order confirmation to delivery
- Warranty
- 3 years, parts and workmanship
Closely related versions have their own guide: BMW M6 F06 / F12 / F13 4.4TT, BMW 335i N55 E90 / E92 / E93 3.0T, BMW 535i N55 F10 3.0T, BMW M135i N55 3.0T.
The N55: the endearing single-turbo that the factory exhaust silences
The 3.0L N55 is the single-turbo straight-six that preceded the B58: linear power delivery, a naturally deep and mechanical sound, and robustness proven across hundreds of thousands of units. It is an engine with genuine character, highly prized for tuning. On your 640i F1x, the factory exhaust, sized for discretion, holds back the essentials: the deep tone, the metallic harmonics and the crackles on the overrun.
The ROG exhaust removes these unnecessary filters. The N55 gets its deep voice back, with valves that give you the factory discretion on demand.
What makes up the exhaust on your BMW 640i N55 F06 Gran Coupé
An exhaust system is best understood in two parts. Here is what each one does, and what ROG replaces.
The cat-back is the complete exhaust system
It is everything you can see under your BMW 640i N55 F06 Gran Coupé, from the outlet of the front section to the tips: pipes, silencer, valves. Routing, silencer, valves: this is where the sound is shaped, and where we focus our research and development.
The front section, where the catalytic converter sits
On your BMW 640i N55 F06 Gran Coupé, it is the downpipe, the pipe leading from the turbo. It contains the factory catalytic converter: the second restriction in the exhaust, after the silencer. Changing this part remains a choice: it pays off mainly with an ECU remap, which turns the freed-up flow into power.
Your BMW 640i N55 F06 Gran Coupé in figures
What an exhaust changes straight away is the sound, the engine's breathing and the weight at the rear. For more power, add an ECU remap.
Power
Torque
Published factory and Stage 2 figures.
With or without an ECU remap, the exhaust fits and works. But it is an ECU remap at an approved tuning centre that truly unlocks your BMW 640i N55 F06 Gran Coupé, and that is what we recommend.
To be transparent: the exhaust alone brings a moderate gain, linked to the reduced back pressure, which is especially noticeable in throttle response on a single-turbo engine. The real unlocking comes with Stage 2, the exhaust plus an ECU remap at an approved tuning centre. The N55 has been proven in tuning for more than ten years: the figures above stay well within its comfort zone.
Configuring your exhaust, step by step
4 choices, in the same order as the product page configurator.
-
Step 1 of 4: Material: stainless steel or titanium
For your BMW 640i N55 F06 Gran Coupé, the exhaust costs €2,190 in stainless steel and €2,690 in titanium.
304 stainless steel
€2,190
- Weight
- Baseline
- Sound
- Full and rounded
Durable, corrosion-resistant, with a rounded, full sound: the most popular option.
Titanium
€2,690
- Weight
- Around 40% lighter
- Sound
- Metallic, crystal-clear
For the same design, it weighs around 40% less than stainless steel. A more metallic note at high revs and a look all of its own, from brushed to blued.
Both materials age well: 304 stainless steel copes with winter and salt, and titanium does not rust. Stainless steel or titanium: what really changes.
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Step 2 of 4: Front section: downpipe and catalytic converter
Optional: the downpipe on your BMW 640i N55 F06 Gran Coupé, with its catalytic converter. Sound rating out of 10, valves open: the factory exhaust sits at 3.
Cat-back only
Included
7/10Factory emissions control
Nothing changes at the front: the cat-back alone is already enough to change the car.
200-cell sports catalytic converter
+€700
8/10Road use and inspection
The everyday compromise: emissions control is still there, and breathing improves noticeably.
100-cell sports catalytic converter
+€700
9/10Inspection: depends on local rules
One step further: more flow, a more aggressive sound, reduced emissions control.
Decat
+€440
10/10Track use
Everything unleashed: maximum flow and unrestrained sound, for the track.
Sound intensity, on a scale of 0 to 10
- 10/10Decat downpipe + ROG cat-back
- 9/10100-cell sports catalytic converter + ROG cat-back
- 8/10200-cell sports catalytic converter + ROG cat-back
- 7/10ROG cat-back only, factory catalytic converter retained
- 3/10Factory exhaust, for comparison
Valves open. With the valves closed, every configuration becomes discreet again.
What about the engine warning light? It can appear with a sports catalytic converter: the downstream oxygen sensor reads a different level of cleaning from the factory unit. It is not an engine fault, and it is dealt with by an ECU remap or a diagnostic tool. With a decat, an ECU remap becomes necessary. If it happens to you, call us and we will point you in the right direction. Passing vehicle inspection with a sports exhaust.
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Step 3 of 4: Valves: ROG remote or factory control
Two ways to control the valves on your BMW 640i N55 F06 Gran Coupé.
ROG remote
The simplest solution: a control unit in the boot and a remote, open or closed at the press of a button, whatever mode you are in. A question while fitting? We will get back to you.
Factory control
- Only for vehicles fitted with factory valves
- Controlled by the drive modes
Does your vehicle have factory valves? The exhaust keeps their existing control: the drive modes operate the valves, as before, with no added electronics.
On a long journey, what matters is the absence of drone at a steady speed. With the valves closed, the exhaust keeps the cabin calm; the show is still there whenever you ask for it. More about exhaust drone.
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Step 4 of 4: Tips: the visual signature
Match the tips to the style of your BMW 640i N55 F06 Gran Coupé, understated or bold. A particular finish in mind? Send us a photo and we will look at it together.
- Stainless steel
- Black
- Carbon
- Blued titanium
- M Performance style carbon
The ROG sound signature on the N55
The N55 has a deeper, more mechanical timbre than the latest straight-sixes. Our exhaust brings it to the fore: an assertive presence from idle, a raw, full climb through the revs, and crisp crackles on the overrun with the valves open. With the valves closed, the car regains a discretion that is perfectly suited to everyday use.
From order to fitting
-
Configuration
You choose the options for your BMW 640i N55 F06 Gran Coupé and enter its VIN, found in box E of the registration document or at the base of the windscreen.
-
Check
We confirm compatibility with your car before we build it.
-
Manufacturing
Made to order, for your BMW 640i N55 F06 Gran Coupé.
-
Delivery
Free, insured delivery, with tracking sent on dispatch.
-
Fitting
Clamps and gaskets, no welding: two hours on average at the garage of your choice.
20 working days from order confirmation to delivery
- Warranty
- 3 years, parts and workmanship, from the date of delivery
- Payment
- In instalments with Klarna
- Installation
- At the garage of your choice
What about the manufacturer's warranty? In Europe, fitting a part from another brand is not enough on its own to void it; the manufacturer has to prove the link between that part and the fault. Our article on the manufacturer's warranty.
Our recommendations for your BMW 640i N55 F06 Gran Coupé
-
Daily driving
€2,190
- Stainless
- Cat-back only
- ROG remote
Your BMW 640i N55 F06 Gran Coupé stays easy to live with, the factory emissions control is retained, and you open the valves whenever you decide.
View this configuration -
Fast road
€3,390
- Titanium
- 200-cell downpipe
- ECU remap
For great roads: more voice and more response, while staying road-friendly.
View this configuration -
Track
€3,130
- Titanium
- Decat downpipe
- Stage 2
The most extreme configuration, for track use only.
View this configuration
These profiles are starting points. The right choice is often made in five minutes on the phone.
BMW 640i N55 F06 Gran Coupé: your questions
How much power does an exhaust add on the BMW 640i N55 F06 Gran Coupé?
As standard, the BMW 640i N55 F06 Gran Coupé produces 320 hp and 450 Nm. Without a remap, the exhaust transforms the voice and lightens the rear; it is the ECU remap that increases power. With a Stage 2 build, the published figures reach 390 hp and 590 Nm.
Stainless steel or titanium: which material for the BMW 640i N55 F06 Gran Coupé?
For the BMW 640i N55 F06 Gran Coupé, the ROG exhaust costs €2,190 in stainless steel and €2,690 in titanium. Choose stainless steel for value for money and a rounded sound, titanium to save around 40% in weight and get a clearer tone.
Do you need to replace the catalytic converter on the BMW 640i N55 F06 Gran Coupé?
No, the cat-back alone already does most of the work on the BMW 640i N55 F06 Gran Coupé. The downpipe option is for those tuning the engine: 200 cells to stay road-friendly, 100 cells or decat for the track.
Will a ROG exhaust pass vehicle inspection on the BMW 640i N55 F06 Gran Coupé?
The cat-back only and the 200-cell sports catalytic converter both keep emissions control: that is the configuration to present, with the valves closed. The 100-cell brings more sound and flow, and whether it is accepted at the emissions test depends on the car and local rules; the decat version is intended for track use on the BMW 640i N55 F06 Gran Coupé.
How is the ROG exhaust fitted on the BMW 640i N55 F06 Gran Coupé?
Fitting needs no welding or cutting and takes two hours on average on a lift. We check compatibility with the VIN of your BMW 640i N55 F06 Gran Coupé before manufacturing.
What price and lead time for a ROG exhaust on the BMW 640i N55 F06 Gran Coupé?
From €2,190 to €3,390 depending on the configuration. Allow 20 working days from order confirmation to delivery. Free delivery, 3-year warranty.
Unsure about your configuration? Give us a call.
Stainless steel or titanium, cat-back only or the complete system: the right choice depends on how you drive and on your BMW 640i N55 F06 Gran Coupé. We take the time to talk it through before you order, with a reply within 24 hours. We are not here to sell to you over the phone: we help you choose, even if that means a cheaper option because it suits the way you drive.
Behind every ROG exhaust is a French team you can actually reach, who know the cars they talk about. More than 500 exhaust systems fitted and a rating of 4.9 out of 5.
Further reading
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