BMW Catback Exhaust Systems for BMW 4 Series F32 (2014+)

Still have the factory exhaust fitted to your B58? You don't know what your missing. Free up lost performance with a new full cat-back exhaust complete with factory valve control!

The B58 engine earned the badge "Worlds 10 Best Engines" four times as of 2023. In 2016 the single turbo straight six found its way to the leaderboards for the first time and followed up in 2017, 2019, and 2020 staying on the charts as one of the best engines in the WORLD.

Our new cat-back exhaust is designed to take out restrictions, maximize flow and give your B58 a signature exhaust note that will excite you on every drive. From the factory your vehicle comes equipped with a combination of three mufflers and resonators that do a great job of silencing the exhaust and restricting flow. There is a center muffler(one restriction), rear section resonator(two restrictions) and a bulky muffler(three restrictions!). With all of those stop gates how do you expect to get the maximum performance out of your vehicle, you simply cannot do so. Lucky for our in-house engineers you no longer have to deal with the quiet and limiting factory exhaust.

To create a cat-back exhaust for this incredible engine the changes happen right after the downpipe. We replaced the factory oval pipe 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 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. Dual 4.0" exhaust tips are optioned to fill out the open space in the rear diffuser and complete the rear profile of the vehicle.

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
Features and Benefits:

Street/Motorsport inspiration
Controlled by factory valves
Reduction in back pressure for increased throttle response, TQ and HP
Dual exit with fitted exhaust tips
Kit Contents:

3.0" front exhaust section (direct fitment to the factory downpipe)
Full 3.0" light weight free-flowing middle muffler sections for better sound, performance and weight savings.
Valved Rear muffler
Clamps and Hardware for an OEM+ install
Optional Turner Exhaust tips - 3.0" Inlet, 4.0" Outlet
Product Development:

Our F 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.

B58 Engine Design:

BMW's first mass produced turbo charged engine, the N54 took the world by storm opening a whole can of worms in the car industry and aftermarket community. A new era of motors were created with the new B58 roughly 9 years after the N54 had been tested and pushed to its limits along with its single turbo companion, the N55. In 2015 the modular engine family was created and the B58 was released into the wild to set a new standard in performance and reliability. Turning back to their roots the B58 engine features a closed-deck engine design similar to the N54 that allows a massive increased in boost pressure capacity and heightened compression ratio. Thought the B58 is similar in weight and size to its predecessor, the new modular engine makes considerably more power right off the rip. With the new block design heat management has been upgraded to reduce the affects of heat cycling to slow the rate of cooling and prevent engine components from failing due to rapid cooling. Just like the N55 the B58 comes fitted with dual vanos, valvetronic and a single twin scroll turbo. Just 8 years experience of this motor we can all agree that the B58 looks like it could be the future of motors to come. This tunable engine has been tested up to 1000hp with the stock block and hosts a platform for the community to break into a whole new class of attainable "supercar killers".

Presenting our Turner Motorsport Performance Cat-Back Exhaust, tailor-made for your 330 or 430. Immerse yourself in an enhanced driving adventure as this meticulously engineered exhaust takes your B46/B48-equipped car to exhilarating new heights. With an unwavering commitment to performance and quality, the Turner exhaust is crafted to unlock the full potential of your F chassis.

Experience a symphony of performance and sound, coupled with a visual upgrade through the quad exit exhaust tips that amplify the motorsport essence of your vehicle. Elevate your driving encounters with the Turner Motorsport cat-back exhaust - unleash the power, reveal the glorious sound, and capture attention wherever you go.

Incorporating their distinctive design principles, this exhaust produces a commanding, deep tone, revealing the bold personality of the revolutionary line of 4-cylinder turbo engines. Leveraging the factory valve control, the Turner cat-back ensures an exciting sound during acceleration, seamlessly blending the high-performance sound with daily driving convenience. Crafted from 1.25mm wall T304 stainless steel, Turner's exhaust boasts superior durability, corrosion resistance, and aesthetic appeal.

Designed with the customer in mind, the installation is a breeze, featuring a straightforward bolt-on process using factory slip joints and mounting locations. Your exhaust system includes all the necessary clamps and hardware for a hassle-free installation. Upgrade your 330/430 with the Turner Motorsport cat-back and let every drive become a statement of power and style.

Upgrading the sound:

Our exhaust allows you to turn up the volume and let the B46/B48 boast its smooth and hearty exhaust tone. Let's be honest, what's the point of owning a B48 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 B48 sound!

How the cat-back is designed:

To create a cat-back exhaust for this incredible vehicle the upgrade happens right at the downpipe. Turner replaced the factory components with oversized 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, this exhaust passes perfectly under the rear subframe for a factory equivalent fit. Positioned in the rear of the car is Turner's signature B46/B48 muffler with a 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. Dual 3.0" 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
Pronounced dual 3.0" Exhaust tip options
17 lb weight savings (Factory - 55lbs, Turner 38lbs)
Kit Contents:

3.0" front exhaust section
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 dual 3.0" exhaust tips
Optional OBD plug-in
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
Optional OBD Plug-In:

The factory-valved muffler is not only controlled by different driving modes like comfort, sport, and sport plus but the RPM also plays into whether the valves are opened or closed. If you are looking for a solution to define whether your exhaust valve is fully opened or closed then you should look into adding an OBD plug-in that features Bluetooth valve control from your phone. During testing, the best way to choose whether your valve is open or closed for your sound preference is through an OBD-linked application on your phone. Included in this kit are optional OBD extensions to not only gain diagnostic function but also gain the ability to influence widgets on your vehicle such as valve position on your valved muffler.