This BMW E61 with a sequential twin-turbo system arrived with software installed by another workshop. The owner reported heavy smoke and disappointing performance. With the existing file, the dyno showed 278 hp and 640 Nm, compared with the cited factory figures of 272 hp and 560 Nm.

The original engine calibration was first installed, with the existing removal of the DPF, EGR and intake-manifold flaps noted. In that configuration, the car produced 260 hp and 540 Nm. AutoChip then prepared its own calibration, which produced 332 hp and 660 Nm on the dyno. Data logs were also used to assess the transition between the turbochargers; the dip during the transition was less pronounced with the new calibration.

Visible smoke with the new file was about half what it had been with the previous one, but it had not disappeared completely. A larger intercooler was still planned, so any benefit from that upgrade was not measured in this project.