Stage 1 ECU Calibration + Handheld Flasher — BMW Z4 M40i

The B58 is a strong, conservative engine with real headroom left in the factory boost and timing tables. It is one of the most rewarding platforms we work on.

What the Stage 1 calibration changes

• Boost targets raised within the stock turbo and clutch limits
• Ignition timing revised across the load range, with knock strategy left fully active
• Torque limiters raised to match the new curve
• Throttle response made linear in Sport, left standard in Comfort
• Speed limiter removed
• Overrun character opened up on the sportier drive modes only

Flashing

Written through the diagnostic port with the battery on a stable supply. Your original software is read and archived under your VIN before anything is written, so it can be put back exactly as it was.

Before you order

Tell us your exact year and anything already fitted — exhaust, filter, decat, downpipe. The calibration is built around what is actually on the vehicle, not around what usually is.

Intended for closed-course and off-road use. Check what is legal where you live before fitting.