ECU remapping is the process of modifying the software within a vehicle's Engine Control Unit (ECU) to optimise its performance, fuel efficiency, and drivability. This involves adjusting parameters such as fuel injection, ignition timing, and boost pressure to suit the specific characteristics of the engine and the driver's preferences. The remapping process is typically carried out with the vehicle on a dynamometer (dyno), where the changes can be monitored and fine-tuned in real-time to ensure that the engine operates at its peak performance while maintaining safety and reliability. By developing custom software maps on the dyno, technicians can achieve a tailored setup that maximizes the vehicle's potential.