The honest answer: 4–8 weeks from starting structured learning to completing a first competent Stage 1. Not safe to sell yet, but technically sound.
To make a first Stage 1 you’re confident to sell: 3–6 months.
Week 1–2: Learning to navigate the ECU file. Finding maps, understanding the torque model structure.
Week 3–4: First modifications in a test file.
Week 5–6: First complete Stage 1 on a real file.
Month 2–3: Validation. Dyno test, road test, thermal cycling.
Month 3–6: Doing it again on 5–10 different files. Building muscle memory.
What slows most people down:
Not the calibration itself — the file navigation. Structured learning compresses this dramatically.
The fastest path: structured fundamentals → real practice files → supervised first calibration. That’s the structure of Diesel Fundamental + Diesel Practice.