Grail 3-inch exhaust system suitable for BMW M4 F82 / F83 (S55) – Valve system

The S55 in M4 – uncompromising sound, no registration required on the road

The BMW M4 F82 Coupé and F83 Cabriolet with SThe 55-biturbo is, for many, a must-have. M-Fans of the most characterful inline six-cylinder engines-M-models. What BMW acoustically reduces from the engine with its factory-installed silencers is clearly audible – the GRAIL valve exhaust system eliminates this. Fuller, more powerful. M-Sound in Sport mode, classic S55-characteristic, subtle in cruise.

Completely made of L304 stainless steel, handcrafted in Germany. ECE type approval – therefore registration-free in all EU vehicles with standard approval. Ready to drive immediately after installation.

With or without OPF – both variants available in the configurator

The 3-inch system is available for MFour models are available with and without a gasoline particulate filter. Both versions deliver genuine GRAIL sound – the difference lies in the acoustic intensity:

• With OPF: Despite the OPF in the system, the system gets really loud and delivers a full, rich sound. S55-inch sound. Slightly warmer in character, with more midrange presence – but definitely not a subdued system. Anyone driving a car with an OPF (Otto Particulate Filter) will be acoustically very well served here.
• Without OPF: Brutally loud. Without the OPF damping, the SThe 55-hp biturbo engine can truly shine – more aggressive, clearer, and acoustically a whole class above the OPF version. And best of all: still fully legal and registration-free thanks to ECE type approval.

Note: For MFor the 4 models without OPF, there is also a 3.5 inch GRAIL system available – this is a separate product in the shop for those who want even more throughput.

Equal Length or Standard Piping

A second option is the piping – a detail that is important for S55-experts know that it makes a big difference:

• Standard piping: Classic, asymmetrical pipework – compact, direct, with classic GRAIL sound
• Equal Length Piping: Both banks are guided by pipes of exactly the same length. This creates a more homogeneous exhaust pulsation, a more harmonious sound signature, and more even flow characteristics. For S55-inch setups with a focus on sound characteristics are the premium option.

Flap control – factory-installed

The MThe F82/F83 has its own exhaust flap control system as standard – the GRAIL takes over this completely. No additional flap control is necessary, no wiring, no remote control.

• In the M-Sport mode opens the flaps fully – full GRAIL sound
• In Comfort mode they remain closed – discreet and ECE-compliant

Plug-and-play connection to your OEM control unit M4 – Operation as usual, sound like never before.

Configuration in the configurator

Before ordering, you select the following factors:

• OPF status: With or without a gasoline particulate filter
• Piping: Standard or Equal Length
• Tailpipe color: brushed stainless steel or black

Unsure about the configuration? Send us your VIN via WhatsApp or contact form – we'll check your OPF status. M4 and advise you before ordering.

Tailpipes – 4x 100 mm round

The system comes with the classic M-4-pipe look: four round 100 mm tailpipes. This keeps the appearance close to the OEM look.M-Look of the F82 / F83 and harmonizes perfectly with the factory or aftermarket diffuser.

• Brushed stainless steel: Classic sporty, high-quality rear
• Black: A subtle yet aggressive look – goes well with the black package and dark rims.

Material & workmanship

LMade entirely of 304 stainless steel, with CNC-precision machined components. The silencers were specially designed in the GRAIL sound lab. S55-biturbo tuned – with switching logic for both OPF and non-OPF variants. Flow-optimized pipe routing minimizes exhaust backpressure. The flaps, made of solid stainless steel, switch precisely and are reliably suitable for everyday use.

Highlights

• Specifically designed for BMW M4 F82 / F83 with S55-Biturbo
• ECE type approval – registration-free within the EU
• Available for M4 with or without OPF
• Choice between standard or equal length piping
• 3 inch L304 stainless steel, handcrafted in Germany

Order with installation from FLOW DOWN®

FLOW DOWN® is an official GRAIL partner in the Ruhr area. When you order with installation, you'll receive our fair deposit payment model:

• 50% deposit upon order placement – we will then order the system from GRAIL
• As soon as the system arrives at our workshop, we will arrange an installation date with you.
• You only pay the remaining amount after the installation has been completed – not before.

Important: The deposit payment option applies exclusively to bookings including installation and is only available via prepayment/bank transfer. PayPal or other payment methods are not accepted for this service.

Swiss suitability assessment

Upon request, you can receive a Swiss suitability assessment for the GRAIL system for an additional fee. If interested, simply contact support.

Suitable vehicles

• BMW M4 F82 Coupé with OPF
• BMW M4 F82 Coupé without OPF
• BMW M4 F83 Cabrio with OPF
• BMW M4 F83 Cabrio without OPF
• BMW M4 Competition F82 / F83

Note: For MFor the 4 F82/F83 without OPF, there is an additional GRAIL exhaust system in 3.5 inches available in the shop (separate product). This system here covers the 3-inch version for both OPF configurations. Not suitable for: M3 F80 (own system), M3 G80 / M4 G82 / G83 (S58-engine, own facilities).

scope of delivery

• GRAIL 3-inch flap exhaust system suitable for BMW M4 F82 / F83 (in your chosen variant)
• 4x 100 mm round tailpipes in brushed stainless steel or black (depending on selection)
• mounting material
• ECE type approval as proof for the vehicle

Information on admission

Registration-free thanks to ECE type approval – applies to all EU vehicles with standard registration. The non-OPF version is also legal and requires no registration. For imported vehicles with different operating permits, please check registration requirements before ordering.

All brands, model names and manufacturers mentioned in this shop such as AUDI, BMW, Hyundai, Kia, Toyota, VW, Tesla are used solely to describe the compatibility of our products . They have no connection with the respective brand owners and, unless expressly stated, they are not original parts from these manufacturers.

FLOW DOWN® is an independent supplier of tuning and accessories. The use of the brand names mentioned is for guidance only and does not constitute a collaboration, licensing or approval by the respective rights holders . All trademark and name rights are held by their respective owners.