These days the power and performance of most cars are limited, not by any particular mechanical factor, but by the software running in the engine control unit (ECU).
Computer algorithms running behind the scenes while you’re driving a modern car to affect all sorts of parameters, such as ignition timing, air/fuel ratio and turbocharging boost pressure. New car engineers typically set these parameters at the factory to meet product marketing targets such as power level, fuel economy and emissions, and that means new cars are rarely fully optimised for ultimate performance.
What is engine remapping?
Engine remapping or chipping companies specialise in altering or replacing the software in a car’s ECU, changing how it performs and potentially removing any restrictions on its potential. The old way of doing it involved swapping a circuit board or chip inside the ECU, but nowadays the new software is often installed via your car’s diagnostic port via a laptop or a handset provided by the remapping company.
Chipping turbodiesel engines can increase economy by seven to 10 percent because it adds torque lower down the rev range. This means the engine doesn’t have to work as hard as before. It’s these turbo diesel engines (often known as TDI, HDI, CDTi depending on the manufacturer) that are the cornerstone of the car chipping industry because an engine chip or software upgrade can cheaply add so much to the performance.