ECU Remapping – Custom Remaps vs. Library Maps

You already know how ECU remapping can improve your car’s performance: more horsepower and torque, smoother handling, better fuel economy. Now all you have to do is find someone to do the job. You will probably notice that some companies advertise custom or personalized maps and other companies talk about using library maps. It is really important to know the difference between the two types of reallocation. Custom reallocation can be more expensive, but it has significant advantages that make it worth the cost.

Custom or custom remapping starts with the file that is in your car’s ECU at the moment. The technician downloads the car’s original ECU map and then modifies parts of it to improve engine performance. Files for many different processes are adjusted with expensive software. The technician must understand the best way to recalibrate each setting; in other words, he must know what he is doing.

In addition to the maps that control fuel combustion, the ECU also contains data relevant to your vehicle, such as immobilizer information, software updates, manufacturer error corrections, etc. For this reason, only the files that need to be changed are touched during the reassignment; other vital data about the car is left untouched. The map is then returned to the ECU, overwriting the existing file. The service provider keeps a copy of the original ECU file, just in case. Bespoke Remapping is always tailored to your particular vehicle, ensuring the best possible results.

Remapping with a library file is quite different. The technician does not use the original ECU file of your car. Instead, a modified ECU map is chosen from a library of perhaps 10,000 generic files. The library file is copied back to the car’s ECU, overwriting everything including vehicle-specific information that might have been in the original file.

Now this collection of library files has a shady past. It consists of ECU files that someone compiled from unknown sources, copied onto a CD and sold for a few pounds on the Internet. Many, if not most, of the ECU files were stolen from professional remappers. As a result, you really don’t know anything about the quality of the files or how they might affect your engine.

Remapping the ECU with a library file is a mistake that can have dire consequences. The library file may not contain the immobilizer software that keeps your vehicle safe. You will not have any recent software updates or crucial bug fixes. And let’s not forget that a service provider using library files is likely cutting corners in other ways, with cheap tools and minimal technical training.

What happens when you replace a vehicle’s unique ECU map with a library file? Certainly the engine could make more power after the remapping, but there’s no guarantee that the improvement will be as expected. Your engine system can develop sudden failures and stop working as it should. The ECU could freeze up and become inaccessible, so you won’t even be able to repair the damage. Without the normal security features, your car could be more easily stolen. And worst of all, you may be forced to spend a lot of money replacing the ECU or repairing the engine.

Now that you know why custom maps are so much better than library maps, how do you find someone to get the job done? First of all, make sure that the company actually offers custom remapping performed by qualified technicians. It is not difficult to know if it is a professional or an impostor. Just ask the technician a few questions about how the remapping is done, what type of files you use, what engine settings are changed, etc. A qualified and experienced person will be able to perfectly explain the finer points of the reassignment process to you. And if anyone mentions library files or tries to convince you that library files are just as good as custom files, cross them off the list.

There’s nothing wrong with shopping around, but don’t make price the deciding factor. This is a high-tech industry and technology costs money. If you find a service provider with very low prices, ask yourself why. In all likelihood they are using library files and cheap tools to remap.

You should also make sure of the after sales support of the company. Is there a trial period after reassignment? Do they keep a copy of the original map in case you ever want to change it back? Does the labor come with a guarantee? Does the company guarantee improvements in BHP, torque and fuel economy? Make sure you are satisfied with the answers to these questions

Remapping the ECU is an effective way to increase engine performance, but if it’s not done correctly, it really puts your car at risk. There is no doubt that bespoke or custom remapping is a better option than remapping with library files. You’ll get the best results, and just as importantly, protect your expensive vehicle from damage.