BMW F30 320d, B47 engine, Bosch EDC17C50. Stock: 190 hp / 400 Nm. Client wanted Stage 1, no hardware modifications.
Baseline: Three back-to-back pulls logged: rail pressure, lambda, boost pressure, load percentage. Rail pressure topping at 1,850 bar, lambda 1.35–1.4 at full load.
Step 1: Rail pressure — Raised maximum from 1,850 to 2,050 bar. Raised target by 150 bar at high load. Flash. Log. Actual rail pressure followed without fault codes.
Step 2: Quantity — Raised injection quantity at high load by 8%. Lambda now 1.25–1.28. Still acceptable.
Step 3: SOI — Advanced by 1.5° at mid-high load. Exhaust temperature stayed within safe range.
Step 4: Smoke limiter check — No visible smoke, lambda still above 1.2.
Result: Estimated +38 hp / +65 Nm. No fault codes. Lambda in range.
What he learned: Going step by step — not changing everything at once — meant that when rail pressure didn’t reach target on first test, he knew immediately which map was insufficient.
That’s the methodology. This is exactly what Diesel Practice is built around.