S58 Exhaust Guide: G80 M3, G82 M4 & G87 M2

The S58 in the G80 M3, G82 M4 and G87 M2 sounds muted from the factory. Two things do most of that: the particulate filters (OPF/GPF) behind the downpipes, and the resonators and rear silencer. The good news is that the exhaust comes apart in sections, so you can change as much or as little as you want.

How the S58 exhaust is laid out

From the engine back:

1. Downpipes with the main catalysts, one per turbo.
2. Front crossover pipe under the engine.
3. Mid-pipe, which holds the OPF/GPF filters on US cars, plus resonators.
4. Rear section: the valved rear silencer and tips. This is what "axle-back" and most "cat-back" systems replace.

Each section bolts or clamps to the next, so most upgrades go in without cutting.

Rear section (axle-back / cat-back): start here

If you want more sound without touching emissions parts, the rear section is the place to start. Every system below keeps the factory valves working, so you still get a quiet mode for cold starts and highway cruising.

• AWE SwitchPath cat-back: a big gap between quiet and loud, and a deep tone. The Track Edition drops the valves for a louder, lighter, non-valved setup.
• Milltek OPF/GPF-back and axle-back: stainless, well made, a more refined sound.
• Dinan valved axle-back (G87 M2 version): an easy bolt-on that keeps the factory look.
• Valvetronic valved sport exhaust (G87 M2): the lowest-cost way into a valved system.
• Top of the range: Akrapovič titanium slip-on (G87), Fabspeed valved systems and Scorpion half systems for the M3.

A rear section on its own gives a deeper note and a louder sport mode. It won't sound dramatic on its own, because the filters and resonators upstream still damp the sound.

Mid-pipe: the biggest change in sound

The mid-pipe is where most of the change in sound comes from. Swapping it removes the resonators and, depending on the pipe, the OPF/GPF filters.

• Single vs X-pipe vs equal length: a single mid-pipe gives the rawest, loudest sound. An X-pipe blends the two banks for a smoother, higher note. An equal-length pipe, like the Active Autowerke Gen 2 (G87), is tuned for a smoother sound.
• Resonated vs non-resonated: resonated pipes such as the Milltek resonated bypass cut most of the drone you'd hear on the highway. Non-resonated pipes are louder everywhere.
• Other options: AWE non-resonated mid pipe, Dinan high-flow middle, CTS single mid pipe with brace, Scorpion X-pipe and Fabspeed X-pipe.

Want to buy it all at once? The Active Autowerke exhaust bundles pair a mid-pipe with their valved rear section (G87 bundles).

Emissions note: the OPF/GPF filters are emissions equipment. A mid-pipe that removes them is sold for off-road and competition use only. It can also set a fault code until the car is tuned. If your state inspects emissions, ask us before you order.

Downpipes: for tuned cars

Downpipes replace the main catalysts. They help a tuned S58 run cooler and hold boost better. On a stock car they mostly add volume.

• Catted, for street cars: CTS high-flow cats, Milltek with HJS sports cats, Active Autowerke with GESI cats, Scorpion with high-flow cats and Fabspeed sport cats.
• Catless race downpipes like the Spool race downpipe are for off-road and competition use only.

Plan downpipes together with a tune. The car needs one to run them properly.

What we'd do

• Daily driver, more sound, keep it simple: a valved rear section, like the AWE SwitchPath, Milltek or Dinan.
• Weekend car, louder: a resonated mid-pipe plus a valved rear. That's where most of the change in sound is.
• Tuned car chasing power: catted downpipes and a tune first, then a mid-pipe and rear to taste.

Leave in the stock valve wiring unless the kit says otherwise. Every system here works with the factory exhaust button. To control the valves on their own, the Dinan valve remote adds a key fob.

See every exhaust part for your car on the G80 M3, G82 M4 and G87 M2 pages.