The Basics of Engine Tuning i.e. ECU Remapping

An ECU contains the instructions for the fuelling, camshaft position and ignition timing systems to operate based on engine rpm and load. These instructions are known as 'THE MAPS'. Changing these instructions requires us to change the maps.  Hence the word - ECU remapping.

ECU remapping can be carried out through the diagnostic ports or by removing the eprom (chips) from an ECU. Chipping and mapping achieve the same end result.

Car manufacturers have to allow a general safety margin for poor fuel grades and extremes in climatic conditions. They also have to cater for a wide audience who have varied driving styles. Some cars are programmed with an extremely lazy throttle response for those who like it ultra smooth. This doesn't help the enthusiastic driver. Improving throttle response alone can make a huge difference. If you have a Mercedes this really applies to you!

With the use of good fuel grade, power can be improved upon whilst still factoring in some safety margins to minimise the effect of extreme climatic conditions. How much safety margin to leave depends on the experience of the tuner and their means of testing (dyno and real life testing).


Are all ECU Remaps the same?

Just because one ECU remap power claim is equal to another this does not necessarily mean you are getting the same thing! Many people base their decision on the power quoted alone - this is by far the worst way to decide on which remap to choose.

Firstly, power isn't everything. More important is the way the car will drive after the changes have been made. How many of the maps have been altered to work in harmony with each other. This again is down to skill, experience and R&D.

A remapped car by company A will probably drive different to one mapped by company B.


Custom Remapping

There is plenty of talk and type regarding 'custom' remapping. Engine tolerances are extremely small - we know this because we dyno so many cars and one car of the same model will always deliver pretty much the same power (as another as long as the adaptive values are set to zero).

Therefore there is absolutely no reason to custom remap every single 'stock' car. The engines are the same, the vehicles are the same. Our heavily developed ECU software will work the same in each stock car it is fitted to.

Custom mapping is only really beneficial to cars with major changes made to exhausts (headers) or engine internals. Air filters and induction kits do not require remaps. If an induction kit allows more air into the engine then the air mass meter will pick this up and generate the appropriate signals to deliver the correct amount of fuel.

Custom remapping a standard car for which we have already created a very good map is a useless and pointless exercise (apart from revenues gained by unscrupulous tuners) unless engine tolerances between car to car are very high.


Live Remapping

A highly misunderstood and misrepresented process in the tuning industry. Live remapping cannot be done through the OBD port. Live remapping means making changes to the ECU whilst the engine is running and this usually requires one of the following:

- Piggyback ECU

- Aftermarket ECU

- Emulator (these are usually soldered directly in place of the chips/eprom(s) inside the ECU)

Live remapping is like custom remapping in that it's only required for the same reasons as custom remapping would be.


Are ECU Remaps Invisible?

The simple answer to this is NO.

Sadly a majority of chip tuners and tuning companies claim that their ECU remaps are invisible to dealers. Whilst some of them claim that they are invisible to diagnostic equipment only, others insist they are totally invisible.

It is true that diagnostic equipment will not detect any changes to the ECU program, however, it is not true that dealers do not have the ability to detect changes. As an example, Evolve can simply take a read of ANY ECU and tell you whether or not it's been remapped. Now, if we can do this then a main dealer most certainly can.

There is no magic code that can or will hide changes made to the ECU program. The best solution is to load on your original ECU software and not run any warranty risks.


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