Grail exhaust system suitable for BMW 1 Series M140i F20 / F21 (B58) – Exhaust Valve System

description

The GRAIL exhaust system with flaps, suitable for the BMW 1 Series MThe 140i F20 and F21 with the B58 engine combines maximum six-cylinder sound with full road legality. Thanks to ECE type approval, the system is registration-free within the EU and ready to drive immediately. Handcrafted in Germany from L304 stainless steel.

The B58 inline six-cylinder engine of the MThe 140i already makes a statement acoustically – the GRAIL exhaust system extracts everything the last 1 Series with a six-cylinder engine can deliver. Powerful, clear, and with the distinctive GRAIL delta between loud and quiet.

Loud but Legal: You can choose between two control options – the original BMW exhaust valve control or the GRAIL ECE R-59 control for maximum legal compliance. Both options function flawlessly from a technical standpoint, but differ in detail in their noise measurement.

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 140i F20/F21 is offered in various versions. Depending on your vehicle, you must select the correct version 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:

• OPF status: with or without a gasoline particulate filter
• Flap control: Standard BMW exhaust valve control or GRAIL ECE R-59 control
• Tailpipes: brushed stainless steel or black

Unsure which version fits your vehicle? Send us your VIN or year of manufacture via contact form or WhatsApp – we'll check the configuration for you before you order.

Two control options to choose from

1. Standard BMW flap control
The flaps are controlled via the original flap control system of the MThe 140i is addressed – that is, via your vehicle's Sport mode. Technically flawless, however, the factory control is based on an older type approval with different measurement values. In the relevant speed range (20–80 km/h), the flaps can remain open longer, which means that the system may exceed current noise limits in noise measurements.

2. GRAIL ECE R-59 control (for maximum legal compliance)
The GRAIL control system automatically closes the flaps within the prescribed measurement ranges between 20 and 80 km/h. This ensures the exhaust system remains compliant with regulations at all times – even during a current inspection according to ECE R-59 standards. Anyone who... MAnyone who frequently drives a 140i or values maximum safety is on the safe side with this variant.

Highlights

• Specifically designed for BMW 1 Series M140i F20 / F21 with B58 engine
• ECE type approval – registration-free within the EU
• Choice between BMW control or GRAIL ECE R-59 control
• L304 stainless steel, handcrafted in Germany
• FLOW DOWN® is an official GRAIL partner in the Ruhr area

Material

L304 stainless steel, handcrafted in Germany. Durable, rustproof, and high-temperature resistant. CNC-machined components ensure precise manufacturing. Acoustically tuned mufflers deliver a powerful sound without unwanted frequencies, while the flow-optimized pipework ensures ideal exhaust flow and thermal stability.

Available variants

OPF equipment:

• With gasoline particulate filter (GPF)
• Without a gasoline particulate filter (sounds even clearer and more powerful because there is no OPF damping)

Flap control:

• Standard BMW exhaust flap control
• GRAIL ECE R-59 control (for maximum legal compliance)

Tailpipes:

• brushed stainless steel
• black

use

The valve-controlled exhaust system replaces the entire exhaust system downstream of the pre-muffler. Depending on the chosen control unit, the valves are operated either via the factory BMW control unit or the GRAIL ECE R-59 control unit. No additional remote control or wiring harness is 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®

Since GRAIL systems have a longer delivery time due to production requirements, we offer a fair down payment model for orders including installation:

• 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 1 Series M140i F20 (5-door)
• BMW 1 Series M140i F21 (3-door)
• BMW 1er M140i xDrive F20 / F21

Note: Each variant (OPF status × flap control × tailpipe color) is a separate system – please select correctly in the configurator.

scope of delivery

• 1x GRAIL exhaust system with flaps, suitable for BMW 1 Series M140i F20 / F21 (in selected variant)
• Tailpipes in selected variant (stainless steel or black)
• When selecting the GRAIL control unit: ECE R-59 control unit
• 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 designations and manufacturers named in this shop, such as AUDI, BMW, Hyundai, Kia, Toyota, VW, Tesla, serve solely to describe the compatibility of our products. They have no connection with the respective brand owners, and unless expressly stated otherwise these are not original parts from those manufacturers.

FLOW DOWN® is an independent supplier of tuning and accessory parts. The brand names are used purely for orientation and imply no cooperation, licensing or approval by the respective rights holders. All trademark and naming rights remain with their respective owners.