How Diesel Tuning works
Today's diesel engines have many sensors which are controlled by the vehicles ECU. These signals are processed many thousands of times in one second to maintain that the vehicle is running at its optimum efficiency, and keeping the emissions and economy at acceptable levels.
Diesel Engine Managament Programming adjusts specific engine parameters in order to optomise the engine's performance throughout the rev range - thus delivering improved performance and enhanced fuel efficiency.
To understand how reprogramming the ECU improves the vehicle's performance, it is important to understand how the diesel engine works. In a diesel engine it is only air that is drawn into the compression cylinder, this is then compressed and reaches a very high temperature. When the piston is nearing the end of its cycle fuel is injected into the chamber and ignites due to the high temperature of the air. This gives the power to drive the piston down.
There is extra air left in the cylinder after this process, sometimes as much as 50%. When extra fuel is injected into the chamber more torque and power and is created.
Common rail is the central container which delivers the individual injectors with the fuel. The three essential components of a fuel injection system – Pressure, injection and generation are separated, and fuel can be stored at high pressure in the ‘common rail' container. This allows high injection pressure even at slow speeds and provides a fine atomisation of the fuel, which gives a cleaner combustion. The supply of fuel is not related to the engine speed as it is controlled independently at every point along the way improving efficiency. So in the modern common rail system engine there is greater opportunity to control fuel injection at the pre-injection, main injection and post injection stage.
The vehicle's engine control unit (ECU) is the brain of the system, which opens each injector electronically, these signals are processed many thousands of times in one second to maintain that the vehicle is running at its optimum efficiency and keeping the emissions and economy at acceptable levels. The ECU contains a “map” which tells the fuel injection system, for every engine speed and setting, how much fuel to inject into the engine.
Using latest digital technology the electronic control unit can give a driving performance so individual that it as though the original control unit software has been completely changed. Four to eight ignition maps are placed in the memory for the first time that then go into action according to your required driving performance. This means the optimal matching of all control parameters at every level of performance.
This is possible through the use of high performance processors that facilitate the detailed real-time scanning of the ignition maps without influencing the internal protection functions.
A further novelty is the ability of the systems to adapt to the individual characteristics of your vehicle in precisely the same way as your standard ECU adjusts the engine characteristics to your dricing style. Over a short running-in period, the memory function detects the individual data for the differing fuel injection cycles. The information gained in this way provides the basis for the optimisation. The tolerances are then balanced and an optimal result is achieved with every vehicle without having to make any time consuming adjustments by hand.
An enhanced ignition map leads to raised levels of efficiency, which in turn leads to reduced fuel consumption. The increase in torque facilitates a driving performance that requires fewer revs per minute and less accelerator pressure to achieve a given acceleration, therefore significantly lowering levels of fuel consumption. According to driving performance, savings of fuel consumption of between 10% and 20% are possible, meaning that your tuning system pays for itself very quickly.
So why don't the manufacturers do this?
You may have wondered why a manufacturer can have the same engine in different models but they can have different power outputs.
This is not due to the engine mechanics as they are usually built to the same standard, but its down to the software installed into the ECU which governs the engines output.
Manufacturers do this because of the strict emissions regulations and tax bands especially for the company owned driver. Many countries around the world relate their tax levels to the KW output of a vehicle or the emission levels.