If you're a proud owner of a G8X M3 or M4, you already know BMW's latest M cars bring serious performance to the table—but when it comes to sound, there’s still plenty of room to unlock their full potential. Whether you're chasing a raw, aggressive tone or a refined, exotic rasp, the right modifications can completely transform your driving experience. In this guide, we’ll break down how to get the best sound out of your G8X platform using key upgrades like the Valvetronic Designs Equal Length Midpipe, our high-performance exhaust system, the exhaust valve harness, and a properly paired downpipe. Let’s dive into how each of these components works together to deliver the soundtrack your M car deserves.

Equal Length Single Midpipe

The S58's factory exhaust setup leaves it sounding like two 3 cylinders, giving it an unwanted tone. By combining the midsection into a single pipe, we bring the sounds together, resulting in a smooth harmony of pure six cylinder sound. This mid-pipe incorporates an equal-length design that allows for a very enjoyable high pitch sound experience without having to modify your OEM rear section. This mid-pipe connects to OEM downpipes or free-flow front pipes if you choose to upgrade. It will not throw a check engine light and can be combined with any aftermarket axle-back.

Valved Axleback 

In addition to our mid-pipe, the system can be optioned with our Axleback for added sound and performance gains, as well as our valve control unit, allowing you to fully open and close the valves at the touch of a button. This system utilizes our familiar quad chambered muffler design in order to offer a very flexible sound experience for the G80 M3 and M4. The system runs 2.75 inches all the way back and is optimized for the best flow characteristics to improve sound and improve power through the rev range. To finish off the system, a beautiful set of double-layered tips come standard.

Exhaust Valve Harness

The Valvetronic Designs Exhaust Valve Harness for the G80 M3 and M4 is the ultimate plug-and-play solution for taking control of your sound on demand. BMW’s factory valve control can be inconsistent, often leaving your M car sounding too tame when you want it loud, or too aggressive when you want it quiet. Our harness fixes that—giving you full manual control over the exhaust valves with the touch of a button. Whether you want to cruise under the radar or open it up for a full-on performance roar, the harness gives you the freedom to choose. Paired with a full Valvetronic Designs exhaust, it’s a must-have upgrade for any G8X owner who demands more from their exhaust system.

Downpipe

Upgrading to more freely flowing downpipes is one of the most effective ways to unlock both power and sound from your G8X M3 or M4. By replacing the restrictive factory unit with free-flows or high-flow downpipes, you significantly reduce backpressure, allowing your engine to breathe better and produce a more aggressive, raw exhaust note. Paired with a Valvetronic Designs exhaust system, the result is a symphony of turbo spool, crackles, and deep tone that completely transforms the driving experience. Whether you opt for a free-flow (catless) setup for maximum performance and volume, or a high-flow catted option for a balance of power and emissions compliance, both options deliver noticeable gains. It’s important to note, however, that some setups may trigger a check engine light and aren’t legal for road use in all areas—so be sure to check your local regulations. That said, for enthusiasts seeking the ultimate sound and performance combo, a downpipe paired with a Valvetronic Designs exhaust is the way to go.

Whether you choose to install one or all of these upgrades, each component plays a key role in shaping the perfect exhaust note for your G8X M3 or M4. The Equal Length Midpipe enhances the natural tone of the S58 engine, smoothing out the rasp and creating a high-pitched, exotic character. The Valvetronic Designs Exhaust adds volume, aggression, and versatility with valve control, while the Exhaust Valve Harness gives you the power to command that sound at any moment. Add in a free-flow or high-flow downpipe, and you unleash the full potential of your M car's soundtrack. Whether you're carving backroads, hitting the track, or just turning heads on the street, this combination delivers the ultimate auditory experience for the G8X platform—one that’s as thrilling as the drive itself.

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