When a sports exhaust is fitted to a car apparently a re-tune of the ECU is required. For a simple example consider a regular unmodified normally aspirated petrol car which then has a sports exhaust fitted to allow higher rate of air flow. I've read that an ECU tune is required to get the best performance. In this case which maps does the tuner change ?
1 Answer
Timing, fuel delivery ie what is called the characteristic map.
If you want to get to grips with this, read up on the early engine controls such as the J and K systems by Bosch - these were simpler than the newest generation used now and may be easier to understand.