JB4 Tuner – BMW G80 M3 / G82 G83 M4 / G87 M2 (S58 Engine) Massive Power Gains. No ECU Flashing. Fully Reversible.
Unleash the full potential of your S58-powered M car with the BMS JB4 Tuner, the ultimate plug-and-play tuning solution for the G80 M3, G82/G83 M4, and 2023+ G87 M2. Whether you're looking for a subtle bump in power or aggressive track-ready performance, the JB4 delivers customizable maps, real-time data logging, and unmatched tuning flexibility—without touching your factory ECU.
