BMW 340i 3 Series B58 Remap, Tune & ECU Calibration Software (F30 F31 F34 RWD/xDrive) | Stage 1 420bhp, Stage 2 440bhp+, Stage 2+ 460bhp+ | Dyno Proven | OBD Flash & Bench Unlock | Burble/Cold Start Delete | UK

BMW 340i B58 ECU Calibration and Performance Software Upgrade

Transform the way your BMW 3 Series 340i drives with a bespoke ECU calibration designed for the B58 engine. This is a premium software upgrade that delivers serious gains in power and torque with smooth, factory-like drivability. Developed with safety and reliability at the core, it is ideal for drivers who want more punch, sharper response and effortless midrange performance.

Real gains. Real results. Proven on the rolling road

• Stage 1 power increase to around 420 bhp with a strong uplift in torque and response
• Stage 2 setup typically achieves 440 bhp or more when paired with suitable supporting mods
• Stage 2 Plus map capable of approximately 460 bhp and beyond, calibrated for maximum usable performance

Every calibration is verified on our rolling road with before and after power runs, so you can see the improvement in black and white. We also carry out a comprehensive health check to confirm the car is performing correctly before we begin.

Custom mapping tailored to your car

• Fully bespoke engine management software. Not a generic flash
• ECU bench unlock service available for later lockable control units
• Optional features on request: cold start delete, adjustable exhaust burble intensity and duration, GTS style start-up sound, and other driver preference tweaks
• Refined throttle calibration and boost control for smoother delivery and stronger acceleration

Why choose MJ Modifications

• Specialists in BMW B58 tuning and BMW 340i performance software
• Dyno-proven calibrations developed with one of Europe’s leading engine calibration experts
• Our team has installed and tested this software on multiple B58 cars. Feedback from our customers has been excellent for both performance and drivability
• Clear, honest advice and support from initial enquiry to post-install care

Compatibility

BMW 340i 3 Series with the B58 petrol engine, including F30, F31 and F34 models. Suitable for rear wheel drive and xDrive variants. If your ECU cannot be flashed via the OBD port, we can provide a bench unlock service in-house.

Popular search terms our customers use

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Fitting and bookings

Have it installed by the specialists at MJ Modifications in Warwickshire. We can handle OBD flashing or ECU bench unlocks and provide full dyno documentation of the results. To request a quote or arrange an appointment, email info@mjmodifications.co.uk.

Please note: actual figures may vary depending on vehicle condition, fuel quality and supporting hardware.