Grail 3-inch exhaust system suitable for BMW M4 G82 / G83 (S58) – Valve system

description

The GRAIL exhaust system with a 3-inch diameter, suitable for the BMW M4 G82 Coupé and M4 G83 Cabrio with SThe 58-series twin-turbo engine combines uncompromising performance. M-Sound with full road approval. Thanks to ECE type approval, the system is registration-free within the EU and ready to drive immediately. Handmade in Germany from L304 stainless steel.

The S58-series six-cylinder engine of the G-MThe 4 has enormous acoustic potential – but much of it is stifled by the OPF (Otto Particulate Filter) and factory-installed silencer. The GRAIL valve-controlled exhaust system unlocks this potential. M4. This brings out what BMW Motorsport has built into the engine: more voluminous, more aggressive M-Six-cylinder sound with the distinctive GRAIL delta between loud and quiet.

Loud but Legal: The GRAIL uses the factory BMW exhaust flap control system of your vehicle. M4 and behaves exactly like BMW M as specified by the factory. At higher engine speeds and under load, the valves open fully – then the system delivers the full GRAIL sound. Since the valves are controlled exclusively via the factory control unit, the system complies with all ECE regulations and is fully street legal.

FLOW DOWN® is an official GRAIL partner in the Ruhr area and specializes in the professional installation of exhaust systems. Installation is carried out directly at our facility in Essen – cleanly, precisely, and including a functional test of the valve control.

Important: Select the correct variant in the configurator.

The GRAIL facility for the MThe 4 G82 / G83 is offered in several versions. Depending on your vehicle, the correct version must be selected in the configurator. If the wrong version is selected, the system will not fit – please check carefully or contact us beforehand.

You choose from the following factors:

• Tailpipe diameter: 100 mm or 115 mm
• Tailpipe color: brushed stainless steel or black

Unsure which version best suits your vehicle's appearance? Send us your VIN or year of manufacture via our contact form or WhatsApp – we'll advise you before you order.

100 mm or 115 mm – which tailpipe diameter?

Both versions are technically identical in performance, but differ visually:

• 100 mm: Classic, understated rear look – particularly well suited to the clean OEM appearance.
• 115 mm: Significantly more present, noticeably thicker in the diffuser – ideal for anyone who wants a striking, aggressive appearance.

Highlights

• Specifically designed for BMW M4 G82 Coupé and G83 Cabriolet with S58-Biturbo
• ECE type approval – registration-free within the EU
• Flap control via standard BMW control unit
• Tailpipes 100 mm or 115 mm in stainless steel or black
• 3 inch L304 stainless steel, handcrafted in Germany

Material

L304 stainless steel, handcrafted in Germany. CNC-machined solid stainless steel flaps switch precisely and ensure the optimal combination of backpressure reduction and sound. Specially developed in the GRAIL sound lab for the SThe 58-engine developed silencers deliver maximum sound when the flaps are open and maximum damping when the flaps are closed.

Available variants

Tailpipe diameter:

• 100 mm
• 115 mm

Tailpipe color:

• brushed stainless steel
• black

use

The flap exhaust system replaces the entire exhaust system downstream of the pre-muffler. The flaps are controlled exclusively via the factory BMW flap control system – i.e., via the original system. M-Sport mode of your vehicle. No additional remote control or extra wiring harness required.

Professional installation by FLOW DOWN® in Essen is recommended. As an official GRAIL partner, we know the systems in detail and ensure clean installation, correct connection to the damper control, and functional testing.

GRAIL order with installation at FLOW DOWN®

For orders including installation, we offer a fair down payment model:

• Upon placing the order, you pay 50% of the investment.
• We will pay GRAIL in advance on your behalf and order the system.
• You pay the remaining amount after the system arrives at our workshop.
• Then schedule an appointment for the installation.

Important: The deposit option is only available for orders including installation and only works via prepayment/bank transfer. PayPal or other payment methods are not accepted.

Swiss suitability assessment

For customers in Switzerland: Upon request, you can receive a Swiss conformity certificate for the GRAIL exhaust system for an additional fee. If you are interested, simply contact our support team – we will clarify the details with you directly.

Suitable vehicles

• BMW M4 G82 Coupé – from 2020
• BMW M4 Competition G82
• BMW M4 CSL G82
• BMW M4 G83 Cabrio – ab Bj. 2021
• BMW M4 Competition G83

Note: For the BMW M3 G80 Sedan and M3 Touring G81 (same SFor the 58 engine (but different exhaust system geometry), there are separate, model-specific GRAIL systems. Each variant (tailpipe diameter × tailpipe color) is a unique system – please select the correct one in the configurator.

scope of delivery

• 1x GRAIL 3-inch flap exhaust system suitable for BMW M4 G82 / G83 (in selected variant)
• Tailpipes 100 mm or 115 mm in stainless steel or black (depending on the selected variant)
• mounting material
• ECE type approval (paper)

Information on admission

The GRAIL exhaust system has ECE type approval and is registration-free for EU vehicles. For imported vehicles with a different operating permit, please check before purchase whether registration in the vehicle documents is required. The included ECE type approval certificate should be carried in the vehicle.

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.