BMW M2 Competition Exhaust: aFe vs Remus vs MBRP (S55)

A BMW M2 Competition exhaust upgrade is the single most satisfying bolt-on you can make to the F87 chassis — it wakes up the S55 twin-turbo inline-six, sharpens throttle response, and finally lets that 405-horsepower engine sound like it should. But the aftermarket splits into three very different system types (full cat-back, resonator-back, and valved axle-back), and the price spread runs from about $2,065 to $3,596. This comparison puts the four systems we stock most often for the 2019-2021 M2 Competition and M2 CS head-to-head on sound, power, construction, fitment, and value so you can match the right one to how you actually drive.

Why upgrade the M2 Competition (S55) exhaust?

The M2 Competition’s S55B30 3.0L twin-turbo inline-six makes 405 hp (302 kW) at 5,230-7,000 rpm and 406 lb-ft (550 Nm) from 2,350 rpm, and the limited-run 2020 M2 CS bumps that to 444 hp. That engine is shared with the F80 M3 and F82 M4, but from the factory the M2 wears a restrictive muffler and mid-section that muffle the S55’s character. A cat-back or axle-back exhaust reduces backpressure, cuts weight over the OEM system, and unlocks a deeper, harder-edged tone. Because every system here mounts behind the factory catalytic converters, you keep your cats, your emissions equipment, and (on valved systems) your factory sound-flap control — so there is no check-engine light and no fueling drama.

Dyno gains from a bolt-on exhaust on a turbo car are modest but real: aFe measured up to +19 HP and +22 lb-ft on its in-house dyno, and MBRP quotes up to +20 HP and +18 lb-ft. The bigger wins are sound, throttle sharpness, and the roughly 15-25 lb of weight you shed versus the heavy factory system. At our Tampa, FL shop, the M2 Competition is one of the most common cars on the lift for exhaust work, and the questions are always the same: how loud, how much drone, and how legal.

M2 Competition exhaust systems compared at a glance

The four systems below all fit the 2019-2021 M2 Competition (and CS), but they replace different amounts of the factory exhaust. Cat-back systems swap the most tubing for the biggest gains; axle-back and resonator-back systems are simpler installs focused on tone. Prices and tip styles are current NLP Performance figures.

1. aFe MACHForce XP Cat-Back — Best Overall

The aFe MACHForce XP is our top pick because it is the only full cat-back here, replacing the entire mid-pipe and muffler section with 3-inch to 2.5-inch mandrel-bent 304 stainless steel and a high-flow metallic-black muffler. It retains the factory exhaust valves and factory-style hangers, so the M2’s stock sound-flap logic still works and installation is a straight bolt-on. On aFe’s dyno it produced up to +19 HP and +22 lb-ft, the strongest quoted gains in this group, and it finishes with quad 4-inch carbon-fiber tips.

2. Remus Valved Axle-Back — Best for Adjustable Sound

The Remus valved axle-back is the pick when you want to dial the volume up or down on demand. It uses two integrated valves controlled by the M2’s original sound-flap actuators and onboard electronics, so you keep the factory quiet/sport behavior while adding a deeper, throatier tone. Remus steps the tubing up to 70mm from the OEM 65mm to reduce backpressure, and finishes with quad 98mm carbon-insert tips. Owners consistently praise how full and deep it sounds at cruise with zero interior drone — a rare combination for an M2 exhaust.

3. MBRP Resonator-Back — Best Value

The MBRP resonator-back is the best value in this comparison at $2,064.99 — a full $1,500 less than the aFe cat-back while still delivering strong gains of up to +20 HP and +18 lb-ft. Built from T304 stainless with a 3-inch diameter and quad rear-exit tips (carbon-fiber outer sleeve over mirror-polished T304), it uses MBRP’s Active Profile design, which works through the M2’s factory valve hardware to run the tone from quiet to aggressive. It carries MBRP’s Armor Pro lifetime warranty, and because it is a resonator-back it installs faster than a full cat-back.

4. Remus Race Axle-Back — Loudest & Track-Focused

The Remus Race axle-back is the choice for the track crowd who want maximum volume. It drops the valves for a simpler, non-valved race design that is the loudest system in this test, with the same larger-diameter Remus tubing and quad tip layout. At $2,870.64 it sits between the MBRP and the valved Remus, and it is the way to go if you never want the exhaust quiet. Note that, like the valved Remus, fitment requires cutting the OEM system at the factory weld during installation.

Cat-back vs axle-back vs slip-on: what’s the difference?

A cat-back replaces everything from the catalytic converters back — mid-pipe, muffler, and tips — so it flows the most air and makes the biggest power. An axle-back (or resonator-back) replaces only the rear-most section, which is a simpler, cheaper install focused on tone rather than peak flow. A slip-on, like the Akrapovic titanium system many M2 owners covet, swaps just the mufflers for the lightest possible setup. If your priority is power and the fullest sound change, choose the aFe cat-back; if it is tone and easy fitment, an axle-back does the job; if it is weight and badge appeal, the titanium slip-on is the halo option.

Want the ultimate: the Akrapovic Slip-On Line in titanium ($6,550.44) shaves the most weight and pairs carbon-fiber tips with race-bred titanium construction, but it replaces only the muffler section rather than the full system. For most M2 Competition owners chasing the best balance of sound, power, and cost, one of the four systems above is the smarter buy. Pair any of them with a tune and a high-flow intake for the full S55 bolt-on package.

Sound, power, and fitment notes

Every system here mounts behind the factory catalytic converters, so they retain your cats and will not trigger emissions faults on a stock or tuned M2. The valved systems (aFe cat-back and Remus valved axle-back) and the MBRP Active Profile keep drone in check at highway speeds because the flaps can close; the non-valved Remus Race is loud all the time by design. Expect a bolt-on install of roughly 1.5 to 2.5 hours for the axle-back and resonator-back systems, and a bit longer for the full aFe cat-back. Both Remus systems require cutting the OEM exhaust at the factory weld, so budget for professional installation if you are not comfortable with a cut-and-clamp.

For 2016-2018 base M2 owners (the N55 single-turbo car, 365 hp), note that these S55 Competition parts are engine-specific — aFe offers a separate MACHForce XP cat-back for the base M2, and you should always confirm fitment against your exact model year. Not sure which system fits your car or your sound preference? Our Tampa team builds M2s every week and can help you match a kit to your goals.