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BMW Z4 E89: the turbo roadster finds its voice, the exhaust system guide

11 min read

BMW Z4 E89: the turbo roadster finds its voice, the exhaust system guide

A rear-wheel-drive roadster with a retractable hard top, the Z4 E89 in 2.0T form relies on the N20, a lively, torquey turbocharged four-cylinder. With the roof folded, though, it is the wind that dominates: the factory exhaust makes the engine almost mute, a real irony for a car built for driving pleasure. The following pages help you choose between the options of the ROG exhaust, for a Z4 that can finally be heard with the roof down.

Written by ROG Motorsport · Updated

ROG valved exhaust system for BMW Z4 E89

Your ROG exhaust for the BMW Z4 E89

From €2,190 in stainless steel, €2,690 in titanium

Configure my exhaust
Vehicles
BMW Z4 E89 2.0T (2011-2016)
Engine
N20 · 156 to 245 hp · 240 to 350 Nm, depending on the version
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 Z4 E89 2.5L / 3.0L, BMW Z4 G29 2.0T, BMW Z4 M40i G29 3.0T.

The N20: the turbocharged four-cylinder of the Z4 E89 2.0T

The N20 is a 2.0-litre inline four-cylinder fed by a twin-scroll turbo. BMW offered it in several power levels in the Z4 E89; in the reference version for this guide, it is rated at 184 hp and 270 Nm. Its torque arrives early and gives the roadster strong acceleration without having to thrash the engine, which suits the way a convertible is used.

On a roadster, you experience the exhaust more than anywhere else, since you often drive with nothing above your head. Yet the Z4 2.0T's factory exhaust lets through only a discreet whisper. The ROG valved exhaust takes its place with no ECU remap: with the roof down and the valves open, the four-cylinder gains depth; with the valves closed, the Z4 stays pleasant for a relaxed drive.

What makes up the exhaust on your BMW Z4 E89

An exhaust system is best understood in two parts. Here is what each one does, and what ROG replaces.

How the exhaust system is laid out From left to right: the engine, the front section, then the ROG cat-back with its valved silencer and tips.Front sectionROG cat-back: the complete exhaustN20
Valves closed: the gases take the long way through the silencer and the cabin stays calm.Valves open: no more detour, the sound comes out unfiltered.Schematic only; the actual routing depends on the vehicle.

The cat-back is the complete exhaust system

It is everything you can see under your BMW Z4 E89, 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 Z4 E89, 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 Z4 E89 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

Factory156 to 245 hp
Stage 2310 hp

Torque

Factory240 to 350 Nm
Stage 2440 Nm

Published factory and Stage 2 figures. Factory figures vary by version; Stage 2 figures published for the 245 hp version.

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 Z4 E89, and that is what we recommend.

As the N20 is offered in several power outputs, remapping finds considerable headroom on this base. The published Stage 2 figures are shown in the table; the actual result depends on the starting version, the condition of the engine and the tuner. These figures come from engine tuning; the ROG exhaust is the sound complement to it, with no promise of extra power.

Configuring your exhaust, step by step

4 choices, in the same order as the product page configurator.

  1. Step 1 of 4: Material: stainless steel or titanium

    For your BMW Z4 E89, 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.

  2. Step 2 of 4: Front section: downpipe and catalytic converter

    Optional: the downpipe on your BMW Z4 E89, with its catalytic converter. Sound rating out of 10, valves open: the factory exhaust sits at 3.

    Cat-back only

    Included

    7/10

    Factory emissions control

    Nothing changes at the front: the cat-back alone is already enough to change the car.

    200-cell sports catalytic converter

    +640 €

    8/10

    Road use and French MOT

    The everyday compromise: emissions control is still there, and breathing improves noticeably.

    100-cell sports catalytic converter

    +640 €

    9/10

    French MOT pass not guaranteed

    One step further: more flow, a more aggressive sound, reduced emissions control.

    Decat

    +400 €

    10/10

    Track use only

    Everything unleashed: maximum flow and unrestrained 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.

    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 the French MOT with a sports exhaust.

  3. Step 3 of 4: Valves: ROG remote or factory control

    Two ways to control the valves on your BMW Z4 E89.

    ROG remote

    ROG remote for opening and closing the valves

    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.

  4. Step 4 of 4: Tips: the visual signature

    Match the tips to the style of your BMW Z4 E89, 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
    Exhaust tips for BMW Z4 E89

The ROG sound signature on the Z4 E89 2.0T

The N20 has more depth than you would expect from a four-cylinder: a muffled, firm note low down, a sportier grain as the revs rise, with the whoosh of the turbo behind it. The Z4's factory exhaust smooths all of that out, and with the roof down it is mostly the wind noise that wins.

With the ROG exhaust and the valves open, the four-cylinder takes on a fuller, more present sound that accompanies the roadster along a winding road. With the valves closed, the Z4 goes back to running discreetly, suited to town driving as well as long motorway journeys.

Valves open and valves closed: the gas path through the ROG silencer
Valves open, valves closed: the path the gases take through the silencer.

From order to fitting

  1. Configuration

    You choose the options for your BMW Z4 E89 and enter its VIN, found in box E of the registration certificate.

  2. Check

    We confirm compatibility with your car before we build it.

  3. Manufacturing

    Made to order, for your BMW Z4 E89.

  4. Delivery

    Free, insured delivery, with tracking sent on dispatch.

  5. 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 Z4 E89

  • Daily driving

    2 190 €

    • Stainless
    • Cat-back only
    • ROG remote

    Your BMW Z4 E89 stays easy to live with, the factory emissions control is retained, and you open the valves whenever you decide.

    View this configuration
  • Fast road

    3 330 €

    • Titanium
    • 200-cell downpipe
    • ECU remap

    For great roads: more voice and more response, while staying road-friendly.

    View this configuration
  • Track

    3 090 €

    • 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 Z4 E89: your questions

How much power does an exhaust add on the BMW Z4 E89?

As standard, the BMW Z4 E89 produces 156 to 245 hp and 240 to 350 Nm, depending on the version. 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 for the 245 hp version reach 310 hp and 440 Nm.

Stainless steel or titanium: which material for the BMW Z4 E89?

For the BMW Z4 E89, 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 Z4 E89?

No, the cat-back alone already does most of the work on the BMW Z4 E89. The downpipe option is for those tuning the engine: 200 cells to stay road-friendly, 100 cells or decat for the track.

Can the BMW Z4 E89 pass the French MOT with a ROG exhaust?

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 converter makes a pass uncertain, and the decat fails the emissions test on the BMW Z4 E89.

How is the ROG exhaust fitted on the BMW Z4 E89?

Fitting needs no welding or cutting and takes two hours on average on a lift. We check compatibility with the VIN of your BMW Z4 E89 before manufacturing.

What price and lead time for a ROG exhaust on the BMW Z4 E89?

From €2,190 to €3,330 depending on the configuration. Allow 20 working days from order confirmation to delivery. Free delivery in Europe, 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 Z4 E89. 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