BMW
M2 Competition / CS F87 · 2018 – 2021
Unlock the S55's twin-turbo voice — the one BMW only lets you hear in Sport+ with WOT.
- Works on M2 Comp and M2 CS valved exhausts
- Compatible with retained-actuator aftermarket back-boxes
- No coding, no Bimmercode, no faults
- Reversible — fob in glovebox, valves back to stock
Free UK shipping
2-year warranty
Fully reversible
The honest pitch
What this actually does to your M2 Competition / CS
The F87 with the S55 is widely considered one of the best-feeling modern M cars. The S55 also has plenty more to say than the standard exhaust map ever allows.
Slot the modules in, pair the remote, and the M2 finds another half-octave on overrun. Daily it in stealth, weekend it in full chat.
Fitment
BMW M2 Competition / CS F87
Years
2018 – 2021
Install time
~10 minutes
Tools needed
None
Long read
The BMW M2 Competition / CS valve story
The F87 M2 Competition — and the later CS — is widely held up as one of the best-driving modern M cars. The S55 inline-six is also one of BMW's best engines of the last decade and the factory exhaust map keeps a lot of it hidden until you're in Sport+ with the throttle pinned. Off cam, on a part-throttle commute, the M2 Comp sounds polite. It's not supposed to.
Open Valve pins the rear valve open. The S55 then sings at every RPM in every mode. The decel chatter on overrun above 4,000 RPM is the headline change — it sounds like a properly cammed turbo six straight away.
F87 install is one of the cleaner ones. Single actuator, single module, single connector. We can fit this in ten minutes with the boot open. The connector sits high in the boot floor next to the spare wheel well; pull the carpet flap, unplug, plug module inline, refit.
Owners running M Performance valved back-boxes or aftermarket valved Akrapovic systems keep the same connector and the same module works unchanged.
Install — step by step
- 01
Open the boot, lift the floor and the spare wheel cover.
- 02
Pull back the carpet flap on the rear right of the boot — the actuator connector lives here.
- 03
Disconnect the 2-pin grey connector. Plug module inline.
- 04
Velcro the module body to the underside of the parcel shelf.
- 05
Refit carpet and boot floor.
- 06
Pair fob, test on idle.
In the box
- One valve override module (one per actuator)
- Two-button RF key fob (CR2032 pre-installed, spare in the box)
- OEM-pattern connectors — no cutting, no splicing, no scotch-locks
- Printed install card with model-specific photos and a workshop QR link
Fitment notes
- ·F87 M2 Competition (2018–2021) and M2 CS (2020–2021).
- ·Original N55-powered F87 M2 (2016–2018) does not have a flap and is not compatible.
- ·Compatible with all valved aftermarket back-boxes using OEM actuator (BMW M Performance, Akrapovic, Eisenmann, IPE).
BMW M2 Competition / CS — FAQ
Does it work on the M2 CS as well as the Comp?+
Yes. The M2 CS uses the same single rear valve actuator and the same 2-pin connector as the M2 Comp.
What about the original F87 M2 (non-Comp, N55 engine)?+
The N55 M2 had a fixed back-box without a flap. There's nothing for the module to override on those cars.
Will it throw a warning light on the dash?+
No. The module sits in the signal path between the ECU and the actuator motor. The ECU sees a normal actuator response back, so there's nothing to flag. We've shipped thousands of these and not had a single check-engine call linked to the module itself.
Is it reversible?+
Yes, fully. Unplug the module, plug the OEM connectors back into each other, refit the trim — about three minutes' work. There's no permanent change to the car, no part cut, nothing in the ECU. Dealer service visits, MOT, sale to a new owner — pull it out and it's like it was never fitted.
Does it work with an aftermarket exhaust?+
If the aftermarket back-box retains the OEM-pattern valve actuators (most do — Akrapovic, Milltek, IPE, Capristo all run the factory motors), yes. If the system is a straight-through with no valves, there's nothing for the module to override.
Will it work with my aftermarket back-box?+
If the aftermarket box retains the OEM actuator motor (BMW M Performance, Akrapovic Slip-On, Eisenmann, IPE all do), yes — same connector, same install.
Does it cause any cold-start issues?+
No. The module is signal-level only. Cold start, cat warm-up cycle, OBD-readiness — all unaffected. The valve just sits open instead of cycling.
Disclaimer
Open Valve modules are intended for off-road and motorsport use only. Please confirm your car has factory valve-actuated exhaust before ordering — if you're not sure, message us first. Professional installation recommended. Use at your own risk.
