Frankly speaking, the process is not very complicated from the physical point of view. It’s useful to remind some essential features about internal combustion engine work to explant it better. This device is provided with energy by the inflammation (we even can call it a blast) of fuel and air, that appears in the cylinder throughout the third stroke. The quantity of torque directly depends on the force amount, which appears during this process. That’s why, if we want to gain more engine power, there is a need to get more substrate (diesel fuel or petrol and air) to the cylinder for the most powerful explosion.
Chip-tuning achieves the aforementioned goal using variant methods, according to engine technical characteristics. The first scheme modifies fuel delivery process, which enlarges the time of injection. The second scheme makes some changes in the supercharging system. Due to implement of specially modified mapping protocols, the exhausted emissions removal retards, that leads to turbine frequency increase and provides supplementary pressure. Each of the ways result in enlargement of flammable liquid and air amount, which blast in the engine. Moreover, in case of petrol power unit chip-tuning can change the ignition protocol, modifying the spark angle. Nevertheless, in this situation there is always a danger of detonation arise (for example when the quality of fuel is poor the ECU automatically adjusts this characteristic to avoid detonation) and if the petrol engine is equipped with turbine, the owner can achieve more power growth from the improvement of mapping protocols, than from modifying spark angle. That is the reason why the best result of chip-tuning are seen on supercharged power plants.