$595.00 USD
$595.00 USD








The MMX Performance F8X S55 Power Control Module is a clean-sheet alternative to traditional ECU tuning for the S55-powered M2 Competition, M3, and M4. After more than 12 months of in-house development, the PCM is far more than a piggyback box, it functions closer to a secondary ECU, with a standalone PCB running MMX's own calibration and communicating in parallel with the factory ECU to optimise charge air pressure, ignition, and fuelling in real time.
The result is a substantial increase in power and torque across the entire powerband, but delivered the way MMX prefers: smoothly, safely, and reliably, without compromising drivability or efficiency. The PCM keeps the OEM ECU intact and untouched, which is what enables the headline benefit: it's completely removable, leaves no trace, and is undetectable when removed. For owners who want serious gains without committing to a flashed ECU, this is the cleanest path on the platform.
Each module is housed in a finned billet aluminium case, anodised in MMX gloss black, and mounted on a carbon fibre bracket. The wiring loom is vehicle-specific, every SKU corresponds to a particular S55 variant, with calibration tuned for that car's stock output. Installation is plug-and-play into the engine bay sensor harness; no ECU removal, no permanent modifications, no special tools required.
Painstakingly engineered and hand-assembled in the UK to OEM-level quality.
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$595.00 USD
$595.00 USD
This product can expose you to chemicals such as lead and lead compounds, which are known to the State of California to cause cancer or birth defects or other reproductive harm. For more information, visit www.P65Warnings.ca.gov.
For a complete list of chemicals known to cause harm, visit https://www.p65warnings.ca.gov/chemicals.
Under the federal Clean Air Act (42 U.S.C. §7522(a)(3)), it is illegal to manufacture, sell, install, or use any part that defeats or alters a motor vehicle’s emission control system for use on public roads. Unless a product has received an Executive Order (EO) from the California Air Resources Board (CARB), it is not legal for use or installation on any pollution-controlled vehicle driven on public highways.
Some states have CARB-equivalent or independent emissions laws. Customers are responsible for verifying local regulations before purchasing or installing emissions-related products.
All performance, racing, or competition parts sold by this company are intended solely for off-road, closed-course, or competition use on vehicles that are never registered or used on public highways.
Kies Motorsports, LLC sells and markets these products for lawful use only. We do not condone or authorize the use of emission-control defeat devices or any modification that violates the Clean Air Act or state regulations.