ECU remapping, car performance tuning

How it works

Fuel

All modern vehicles use an ECU (Engine Control Unit) to control fueling. When manufacturers write an ECU program for fueling they tend to program around model specification rather than for maximum engine power or best fuel economy. We set the fuel ratio for optimum power at full throttle and this allows us to modify the program at mid range throttle so that overall fuel consumption is improved. Fuel ratio for best power 12.6:1 and Fuel ratio for best economy 15.4:1.

Ignition

Ignition (spark) timing is also controlled by the ECU. This is an area of adjustment that will release power from an engine. A few year's ago it was possible to adjust the distributor and adjust the timing - replacing the internal centrifugal bob weight springs to help with an advance curve. Modern day engines no longer have distributors so the only way to optimize ignition advance is to remap the ECU and give a more advanced timing curve, resulting in greater power and more responsive throttle.

Forced Induction (turbo/compressor)

Forced Induction is the process of using a mechanical system to force more air into the engine. This includes superchargers, turbochargers and other mechanical systems. Both superchargers and turbo's use a compressor to force air into the engine, making it more dense (i.e. more oxygen). When fuel is added this creates a much larger explosion and more power from the engine. These mechanical compressors are controlled by the ECU, remapping the intake boost pressure gains as much as 40% more power.

ECU

An ECU (Engine Control Unit) is the computer that controls the various operations of an engine, i.e. injector duration, fuel/air ratio, ignition timing & forced induction (compressor/turbo charger). Modern ECU’s are very powerful systems which calculate and process the entire engine control. Most ECU’s are now ‘drive by wire’, which means the driver of the car can no longer control the throttle position. It is this total control the ECU has over the engine that makes ECU remapping so effective.

EPROM chip

The engine map EPROM chip is contained within the ECU’s printed circuit board. It is this chip that contains the information the ECU needs to run the engine, this chip is programmed with data to instruct the ECU how and when to inject the fuel, when combustion should begin and how much charge pressure should be applied under all driving conditions.