New G20 340/440 Muffler Delete

Let’s be honest—what’s the point of owning a B58-powered BMW if you can’t hear it? The factory M340i and M440i rear muffler assembly is oversized, heavy, and overly restrictive, muting the deep, aggressive tone the B58 engine was designed to produce. Our Muffler Delete System is the perfect solution for enthusiasts looking to unleash that signature turbocharged inline-six sound without the cost of a full cat-back system.

Engineered and manufactured in-house, this system replaces the factory rear muffler with a free-flowing, TIG-welded 304 stainless steel setup designed to enhance tone, reduce weight, and maintain OE-level fitment and quality. At the front, 3" primary tubing mates seamlessly to your factory midpipe using a durable stainless steel sleeve clamp. At the rear axle, the primary tubing transitions to dual 2.5" adjustable tailpipe sections for a clean, yet aggressive look. These tailpipe sections merge to quad outlets, designed for compatibility with our selection of 3.5" exhaust tips, allowing you to tailor the system's appearance to your liking. Accuseal-style, slip-fit joints allow for easy adjustment, ensuring perfect tip placement inside the factory rear diffuser. The result? A more engaging exhaust note and a clean, motorsport-inspired appearance that transforms your BMW’s personality both visually and acoustically.

Features & Benefits

TIG-welded 3" primary tubing transitions to dual 2.5" adjustable tip sections for a bold, refined look Accuseal slip-fit joints offer full adjustability for precise alignment and perfect tip placement Direct-fit design connects to the factory exhaust at OE cut points using the original sleeve clamps Quad 2.5" tip outlets compatible with Turner tip options in Brushed Aluminum, Black Chrome, or Mirror Chrome Utilizes factory exhaust hangers for a clean, bolt-on installation—no cutting or drilling required Kit Contents:

Mid-Pipes (Left & Right) Crossover Pipes (Left & Right) Tail-Pipes (Left & Right) Logo Bracket & Hardware (2) Accuseal-Style Exhaust Clamps (2) Sleeve Exhaust Clamps (4) Turner Motorsport 3.5" Tips – Choose Your Finish! Product Development

Our G2X M340/M440 Muffler Delete Kit was designed, engineered, tested, and quality-inspected in-house to ensure the highest level of precision and quality through leading-edge product development technology.

Introducing our Turner Performance Cat-Back Exhaust for your G20 M340! Precision-crafted exhaust that elevates your driving experience with a new level of excitement. Designed with our commitment to performance and quality, this exhaust is meticulously engineered to unleash the true potential of your M340. In tandem with performance and sound, our cat-back exhaust enhances the visual aesthetic with upgraded quad exit exhaust tips that complement the overall motorsport nature of the M340 and replace the fake factory exhaust tips. Upgrade your driving experience with our cat-back exhaust for your M340! Unleash the power, bask in the glorious sound, and turn heads wherever you go.

Using our signature design principles this exhaust is crafted to deliver a deep, authoritative tone that reveals the true rowdy attitude of the M340. Designed to utilize the factory valve control our cat-back provides an exhilarating sound during acceleration without compromising the daily driving amenities. Our exhaust is manufactured of 1.25mm wall T304 stainless steel for superior durability, corrosion resistance, and aesthetics. Designed with the customer in mind it features a straightforward bolt-on installation utilizing factory slip joints and mounting locations and includes are clamps and hardware necessary for installation.

Upgrading the sound:

Our exhaust allows you to turn up the volume and let the B58TU boast its smooth and hearty exhaust tone. Let's be honest, what's the point of owning a B58 if you're not going to upgrade the exhaust? Our signature muffler design allows you to transfer the exhaust valve from your factory system directly onto your new Turner system. The Turner exhaust signature muffler design allows for two flow paths that change both tone and volume. With the vehicle in eco or comfort mode, the valves remain closed, with the closed valves the exhaust system allows the gasses to flow through the muffler toning down the volume and giving a more refined exhaust note. While in driving modes sport or sport+ the valve opens and the flow path changes to a "straight flow path" essentially turning into a straight-piped exhaust for the least amount of restriction and the most amount of B58 sound!

Upgraded aesthetics:

From the factory, the G chassis comes equipped with fake or imitation exhaust tips, our Turner exhaust allows you to remove the imitation tips from the vehicle and sport a set of 4 true exhaust tips giving that upgraded motorsport styling.

How the cat-back is designed:

To create a cat-back exhaust for this incredible vehicle the upgrade happens right at the downpipe. We replaced the factory components with our full 3.0" T304 stainless steel piping. The true 3.0" exhaust makes its way through the center and rear of the car without the center muffler or resonator to keep the flow to a maximum! With smooth mandrel bent transitions our exhaust passes perfectly under the rear subframe for a factory equivalent fit. Positioned in the rear of the car is our signature B58 muffler with beautiful inlet and outlet piping that creates the perfect exhaust tuning. Featuring relief cut slip joints and fabricated sheet metal brackets the exhaust can be fully adjusted and mounted seamlessly in the factory locations. Quad 3.5" exhaust tips are optioned to fill out the open space in the rear diffuser and complete the rear profile of the vehicle.

Features and Benefits:

Street/Motorsport inspiration
Controlled by factory valves
Compatible with factory and aftermarket downpipes (80mm)
Quad exit with true exhaust tips to replace factory facia
19 lb weight savings (Factory - 65lbs, Turner 46lbs)
Part Design:

Turner In-house designed and engineered using FARO ARM laser scanning technology and SolidWorks 3D CAD modeling for precision fitment.
T304 Stainless Material in a natural finish - 1.25mm wall thickness, back purged and TIG-welded throughout
Full 3.0" Stainless Steel Mandrel Bent Tubing
T304 Stainless Steel 12mm barbed exhaust hangers Tig-Welded in OE locations for precise fitment.​
Strategically placed slip joints provide the most adjustability to obtain perfect fitment
Kit Contents:

3.0" front exhaust section (80mm flange to connect to factory and aftermarket downpipes)
Full 3.0" lightweight free-flowing midsection for better sound, performance, and weight savings.
Valved Rear muffler
Valve extension harness
Clamps and Hardware for an OEM+ install
Optional 3.5" Exhaust Tips
Product Development:

Our G Chassis B58 Valved Catback was designed, engineered, tested, and quality inspected by our Research and Development team at Turner. Nothing but the highest level of precision and quality through leading-edge product development technology including FARO laser scanning for reverse engineering and quality inspection, SolidWorks 3D CAD modeling, rapid prototyping utilizing our in-house 3D printer, and rigorous long-term product testing.