Why the order matters
Cam tuning builds on itself. If the zero point is wrong, every angle you map afterward is wrong too. If the output isn't holding the cam steady, dyno results won't repeat. So we prove each step before moving to the next. The inputs and outputs themselves are covered in the main cam control article.
Step by step
- Start clean. Set every cell in the Cam Angle Map to zero and bring the engine to full operating temperature. Oil temperature and pressure affect how the cam phaser moves, so a cold engine gives misleading results.
- Find true zero. Turn on the Cam Control Input using your values or the defaults, with the Cam Control Output still switched off. Adjust the trigger angle until the reported cam angle reads 0 degrees. With the output off, the cam sits at its rest position, so this is your reference.
- Turn on the output. Enable the Cam Control Output, again with your values or the defaults. With a zero target, the cam angle should stay near 0 degrees. If it creeps upward before settling, reduce the Steady State Duty Cycle.
- Prove it tracks. Raise the Intake Cam Angle Map by 10 degrees and confirm the measured cam angle follows. If it doesn't track cleanly, revisit the control settings before going any further. Our PID tuning guide helps here.
- Test on the dyno. Make runs at 0 degrees, then at each 10 degree step up to the most advance the cam can safely use. Keep everything else the same between runs so the only change is cam angle.
- Build the map. Compare the runs and fill in the map with whichever cam angle gave the most torque at each RPM and load point.
Tips from our dyno
- Log cam target and actual cam angle together. A large gap between them means the control isn't keeping up, and your torque numbers aren't telling you about the angle you think they are.
- Watch ignition and fuel as you change cam timing. Cam angle changes how the engine breathes, so the best angle may need its own fuel and timing refinement.
- Part load matters as much as full load. Use steady state testing, covered in applying load to the engine, to map cruise areas for drivability and economy.
Want us to handle the dyno work? Book a free consultation and we'll talk through your engine.
