Here you will find some technical information on remapping with the history of the related parts and processes that are involved.
During the early 80’s vehicle technology changed dramatically with the implementation of computer technology. ECU’s (electronic control units) were introduced into vehicles in order to improve performance and efficiency. In the early days ECU’s controlled just a handful of processes, with advances in both electronic and computer technology ECU’s now control a vast amount of electronic and mechanical processes. Signals transmitted from sensors located on the engine and chassis provide vital information to the ECU so that real time adjustments can be made. Engine speed, boost pressure, fuel pressure, cam timing, lambda and pedal position are just a few examples of the parameters measured by an ECU and the parameters it can control.
Like your home PC has software (drivers) which controls the computer hardware (CD drive, Speakers. etc.) an ECU also has a piece of ‘software’ or program loaded onto it which controls the hardware components of an engine, this program is often referred to as a map. Although a map file extracted from an ECU will actually contain several maps. E.g. Boost Map, Fuel Pressure Map, Injection Quantity Map, lambda Map, etc…
By extracting the map data from the ECU, the individual maps can be modified and reloaded to the ECU. If these maps are recalibrated correctly, the performance, drivability and efficiency of an engine can be improved. This process is called Remapping.
In most cases the performance of a vehicle with factory settings is so far away from the engines true potential performance it could be said that they are electronically detuned by the manufacturers. Sounds crazy? I know, but there are several significant reasons for detuning a vehicle and it will become clearer as you read on.
When a vehicle is manufactured for global sale it must be able to cope with many different environments. The vehicle must be able to cope with poor quality fuels sold in less developed countries, perform at high and low altitudes, cope with poor or non-existence servicing and also perform with severe differences in temperature. Think about it, a vehicle manufactured in Japan must be able to cope with the high air temperatures of India, but also perform in the freezing winter conditions of Russia. Therefore, when a manufacturer is producing a map for a vehicle to be sold globally, it has to make a compromise, between performance, and the vehicles ability to perform in a number of different environments. Couple this with the fact that there are extremely stringent regulations on the exhaust emissions of new vehicles, not to mention the political pressure of producing ‘green’ vehicles, it is easy to see why manufacturers detune their vehicles from the factory.
Luckily, in Australia we do not have many of the environmental and other issues described above. We have extremely good quality fuels and a very good servicing regime, so we can tune vehicles without having to compromise on reliability. Not only this, we are able to finely tune vehicles so that they perform to their maximum potential in the Aussie environment.
How can you extract so much power from some vehicles? Certain vehicles offer unbelievable gains in power and torque following a Remap, often the vehicles that offer the best increase in power and torque are severely detuned from factory. It is now common practise for a manufacturer to produce one engine, yet offer several different power options. For example, take the new Ford Transit 2.2 TDCI engine, there are four power options for this vehicle: 85 PS, 100 PS, 125 PS, and 155 PS. How is this possible when the engines are all the same size and all have identical hardware? Well it all comes down to the map loaded onto the ECU from factory. Basically the 85 PS engine is a detuned 155 PS engine, the 155 PS model can be tuned to 180 BHP, therefore the 85 PS model can also be tuned to 180 BHP. That’s an increase of 95 BHP!
How is the map altered? Well this is where it starts becoming really complicated and there is not enough space on this page to cover the whole subject, but we’ll try and cover some of the basics.
The internal combustion engine works by burning fuel and air, converting this chemical reaction into kinetic energy. By Remapping an ECU we can alter the amount of air and fuel that enters an engine. On a turbo vehicle we can increase the air quantity by increasing turbo boost pressure and we can also increase the fuel quantity by altering the fuel injection maps. If you alter the amount of fuel and air injected into the combustion chamber you can alter the power, torque and efficiency output. Unfortunately, it’s not that simple, many other factors also come into play when tuning a combustion engine. You must also consider at what point in the engine cycle should the fuel be injected, how long the injection period should last for and at what point the fuel should be ignited. Remapping is about fine tuning and getting the balance correct for that specific engine design.
Here are some of the parameters that are altered during a Remapping process
Injection Quantity, Injection Duration, Injection Pressure, Turbo Boost Pressure, Spark Advance, Pedal Maps, Torque Limiters
ECU remapping can be fun and the increase in performance and efficiency can be truly amazing, but, if not done correctly it can also be dangerous. A petrol engine running too lean with too much timing advance can result in detonation (fuel igniting too early and pushing the piston back the wrong way) – detonation can cause catastrophic engine damage. Diesel engines can also be damaged if too much fuel is injected, internal combustion temps can increase dramatically due to the extra energy created and piston damage can occur. This is why it is important to choose the right company when you decided to have your engine remapped.
So now you have been given a bit of an insight into why there is remapping potential in nearly all vehicles, we will now discuss the different methods of remapping and some history on OBD.
All petrol cars sold within Europe since 1 Jan 2001 and all diesel cars manufactured from 2003, must have OBD (On-Board Diagnostic) systems to monitor engine emissions (although, OBD systems have been fitted to many vehicles since the early 90’s). These systems were introduced in line with the European Directive 98/69/EC to monitor and reduce emissions from cars. OBD equipped vehicles are also fitted with an OBD port, this port is basically a communication port which is designed to allow diagnostic equipment to interrogate and even reprogram the ECU’s fitted to a vehicle. The introduction of the OBD port completely transformed the way tuners accessed the map data stored inside ECU’s.
Forms of remapping/Tuning
Remapping through the OBD port is the most efficient and non-intrusive tuning method, which allows us to yield some truly amazing results without even opening the bonnet. Using specialist remapping equipment, the ECU data can be extracted from the ECU via the OBD port, once the data has been modified the data can then be reloaded back to the ECU via the same process.
Remapping a vehicle through its OBD port is not always possible for a number of reasons, the vehicle may not have an OBD port, the port may be faulty or the ECU may be ‘tune protected’ (systems put into place by the manufacturer to prevent ECU data from being modified via the OBD port). Bench tuning is the name given to the process of removing the ECU from a vehicle and making a direct connection to the internal circuit board of the ECU on the "work bench". Once on the bench there are several different methods of communicating with the ECU and the method used depends on the type of ECU and the internal microprocessor.
BDM or Background Debug Mode is the process of connecting directly to the circuit board of an ECU, using a specially engineered jig to hold the ECU in place while data pins are connected to the circuitry.
Other methods include: Boot Mode, Pin Out, JTAG..etc..
Chip Tuning – ‘Chipping’
Early ECU systems contained EEPROM’s (AKA Chips) which stored the map data. In order to read the data programmed to these chips, tuners often de-solder the chip from the board and place the chip in a chip reader. This data would then be modified and reloaded on to the chip. However, the chips fitted to some early ECU’s were often OTP (One Time Programmable) meaning that although the data could be extracted from the chip, the new modified map data could not be programmed back onto the same chip. In order to overcome this, the tuner will program a new chip with the modified data and solder the new chip to the circuit board. This process is often nick named – chip change.
Since the introduction of multi programmable chips and MCU’s tuners have adopted faster, cleaner and less detectable methods of remapping i.e. OBD and BDM tuning. Although it must be noted that there are still many cars on the road today that have to be chip tuned.
It is also important to remember although all three of the processes outlined above are very different, they are just different methods for achieving the same thing – Remapping.
I hope you have found some of this information useful and now have a better understanding of what remapping involves and how electronic tuning can alter the performances and characteristics of a vehicle.
OBD – On Board Diagnostic
EOBD – European On Board Diagnostic
JOBD – Japanese On Board Diagnostic
OBDII – On Board Diagnostic (American standard)
MIL – Malfunction Indication Light
DTC – Diagnostic Trouble Codes
BDM – Background Debug Menu
EEPROM – Electrically Erasable Programmable Read-Only Memory
ECU – Electronic Control Unit
MCU – Microcontroller