Up-to-the-minute car engines are controlled by a computer. These computers have a “chip” that tells the computer when and how to adjust your car’s timing, its fuel-to-air ratio, turbo boost and different things. Since automobile manufacturers must be competitive in fuel consumption, and comply with emissions and other regulations, they frequently reduce many of these settings.
Performance chips are aftermarket chips that regulate these parameters, often increasing engine power and torque. Some performance chip makers says their chips will increase gasoline engine power by up to 35 horsepower and beyond, and even more in a diesel engine.
The factory chip in an automobile contains a bit referred to a lookup table. The lookup table contains data that inform the engine how to respond under different situation. For example, if you are driving down the highway going 50 miles per hour and you quickly press the gas pedal all the way to the floor, the computer will notice this and ask the chip what to do. The chip will refer to its lookup table and inform the computer how much gas to send to your engine, how and when to shift your car into a lower gear in the case of an automatic, how to regulate the timing and how much turbo boost to provide, if your car is equipped with a turbo charger. In a factory chip, all of these parameters are dictated by the car manufacturer for its own purposes. When you put a performance chip in, this changes the lookup table and adjusts the parameters to give you the high performance without regard to fuel economy, emissions and other performance-reducing constraints.