What is chip tuning?
Thirty to forty years ago, if we wanted more power we had to tune an engine by choosing another calibration of our carburetor, and we had to choose the best ignition curve with our distributor to find the best power on the dyno. With chip tuning we do the same, but because the engine is now completely managed by an electronic control unit (ECU), we have to modify the program by altering fuel- and ignition curves to find maximum power. The program is stored in an EPROM called chip. Therefore we call it chip tuning.
How can we gain power and torque with chip tuning?
By modifying the ignition- and fuel curves in a good way, we can gain power and torque. We can only gain significant power with ignition modifications if we use the best available fuel. So driving with 95 octane cannot give us a significant gain. We choose the minimum fuel amount to come to lambda 0,9 (atmospheric) or 0,82 (turbo) to find maximum power. We can eliminate flat spots in the power curves. Very important is that every mechanical modification on an engine (like camshafts) gives only power gain if the program matches this modification. We have to tell the ECU what he has to do by reprogramming the unit. For atmospheric engines the gain is between 5 and 10%. For turbo engines this can go up to 30%, because we can manage also the turbo strategy. The best way to tune turbo engines is to try not to go higher in turbo pressure than the maximum original pressure, but to go as quick as possible to that point and hold this pressure as long as possible by help of the program.
Why isn't it done by the car manufacturer?
The car manufacturer is limited in his programmation due to the fact that he has to find a compromise between many different aimed objectives and regulations when programming a car:
- First of all, there are the anti-pollution laws for the different countries. The easiest way for high production is to give the same severe program for all the cars independent which country they will be delivered.
- Most of the time the programs are more severe than the law describes, so the manufacturer has no problems in the near future. Because he cannot program every engine separately, he has to choose a save program for all his engines where the mechanical tolerances differ from one to another.
For this reasons, if we want to make power gain with chip tuning we have to do every car individually to find the limits of the tolerances of that car. It is normal that one car has not the same tolerance as another one and therefore needs another program. All the tuners or companies who try to sell the same program to all the cars of the same type are only interested in the commercial side of the business with all its possible technical consequences. A bad program can destroy your engine.
Will I have a higher consumption after the tuning?
We have a better combustion if the ignition curves are optimized. Because we have more power and torque, we don't need to push the accelerator as hard as before. Some cars are even too rich for maximum power at certain points. For the best economy, you can use the commercial fuel with the highest octane. So it is better to use 98 octane than 95 octane, even when the car manufacturer allows you to drive 95 octane. You will economize on the price difference in fuel, but at the end you will lose money due to the increase of fuel-consumption. Moreover, you will lose power as well. In most cases of tuning only 98 octane is allowed because the engine is tuned for that octane to obtain maximum power. A much higher fuel consumption than original, means that you didn't use the right fuel for the modified program, or that the tuned program is not a good one, but one which has too much pré-ignition and/or too much fuel.
Is chip tuning better than an additional black box?
Both are good if they are made properly. Above you can read the difference between a good and a bad chip tuning, which is the same for the so called black box. This is an additional box that modifies the data in an external way. Everything depends on the way this additional box works, which data it takes as input data and in which way it delivers output signals. Some black boxes receive not enough input data to work well, and therefore deliver not the right output signals. For example some diesel boxes are directly placed between the wire loom and the diesel pump. So these boxes only receive a 12V alimentation and increase the fuel injection in a constant way. If the engine is idling or on full power the amount of fuel is the same. You don't have to be a technician to understand that if the quantity of extra injected fuel is chosen for maximum power, this same amount is too high at part throttle or low revolutions. Here the maximum power can be achieved as with other systems, but you have flat spots, hesitations on part throttle and low revolutions. Furthermore, you get a lot of black smoke. If the same black box is made in a way that it can modify the extra injected fuel (output) in function of the throttle position and the turbo pressure (input signals), and if it is well programmed, it can be as good as chip tuning. This is the way our diesel black boxes work. You can understand that the technical way to achieve this is more sophisticated and therefore more expensive than the first systems described above. The advantage of this system is that the customer can leave his ECU original, which is preferred by both the dealer and the main distributor.
What when my dealer reflashed my ECU with an update back to original?
It can happen that your official workshop dealer has to reflash your tuned ECU with an update, or even that they have done it accidently. The car will be back to original. No problem, the customer comes back and if his tuning has been done within the last 3 months we retune the car starting from the latest original program for free.(0,00 €). So he can enjoy again his tuned car with the latest factory update.
Dangers of bad chip tuning?
Imported programs from other countries can be dangerous if for example the fuel quality is better in that country, than in the one we are driving the car. The program has to be made special for the used fuel quality.
- For petrol engines:
- Too much pre-ignition gives a higher fuel consumption and can even destroy your engine by detonation.
- Bad air/fuel ratio's:
- Too rich mixtures can give you a big fuel consumption and even cylinder washing which will take away the oil film and destroy the engine.
- Too lean mixtures give too high combustion temperatures, favorite’s detonation and can also destroy your engine.
- For diesel engines:
- Too rich can give you a high fuel consumption and even cylinder washing which will take away the oil film and destroy the engine.
- It will destroy your cat, DPF and your ré-combustion system (EGR).
- For all turbo- or supercharger engines:
- Too high turbo pressures may also destroy your engine in all possible ways, cylinderhead gasket, pistons etc. .
For turbo diesels, the most gain is achieved by enriching the injection in a good way , which gives you automatically a turbo pressure amount of nearly 0,1 bar, which is save with the fuel amount. It is not necessary to program higher boost pressures, but maybe only the turbo strategy to achieve quicker the maximum original boost. You need much higher turbo pressures to obtain a power gain, which is not reasonable.
Please take in mind that a diesel engine has to do a lot of mileage!