Here's the DPTune FAQ page that answers some of our questions. Especially question #7.
1. What is flash tuning?
Flash tuning involves altering the parameters stored within the ECU. This is done by reading the code stored on the ECU, altering it, and writing it back on. In a very simplistic way, it is the same as updating your iPod with new firmware.
2. What is altered?
Many parameters can be altered; it is dependent on the car. We can raise the engine rev limiter, as well as remove the vehicle speed limiter. For example, with the MazdaSpeed3 , some of the base parameters altered include boost, fueling and spark advance.
3. How are Tunes written?
Flash tunes are the result of a large amount of work. Many hours are spent accessing and decompiling the memory on an ECU. Particularly the newer more modern units. Once this process is finished, the resulting information needs to analysed and arranged in such a fashion, one can confidently understand where all the various parameters controlling the motor are located. This is a very lengthy process. It can take months. Finally, large amounts of time and effort are then spent in testing various changes in order to optimise the final product.
4. Can my Dealer detect a tune?
One of the reasons we check and modify the file from your car is to retain the chassis number and hardware info possibly embedded within the data. This means that when the ECU is scanned, it will return correct information for your car. This helps make it basically undetectable, and why it is important to be car specific! However, if they hook up to the OBD diagnostic port and log boost parameters and find an abnormally high boost, they'll be asking you questions!! There is no way to be 100% sure they will not find out you have modified the car! Same can be said for most forms of modification.
5. What happens if my Dealer updates my car?
This seems to be a major concern for some. Simple answer is, you will loose the tune and return to factory settings. Car updates are done normally when the Manufacturer decides an issue can be solved. Do not believe that every time you put your car in for a service, the ECU/PCM will be reflashed with new factory firmware, this is not usually the case. Please remember the car is yours, and you have the ability to say no to any updates. This will prevent the new tune being lost. However, if this should occur, simpy contact us for a free reload of your reflash.
6. If I disconnect the battery, will I loose the tune?
No. If you disconnect the battery and then pump the brake pedal a few times to remove any remaining charge, it will reset your ECU. When you reconnect the battery the same parameters will still be stored on your ECU.
7. What if I have or add mods?
There is normally no need to have a custom tune for mods like exhaust, TMIC or CAI's. The ECU will deal with these mods happily. This applies to mods installed before and after a flash tune. The ECU will relearn any parameters it needs to for proper operation. Experience shows that adding mods normally enhances the tune, as it does under a stock tune. A custom tune is advised for major work such as heads, cams and modifications that may radically alter sensor data fed to the ECU/PCM.
8. Why is Flash Tuning expensive?
Often people ask, and endlessly discuss on forums, why the cost appears high considering that all we do is plug a laptop into your car - after all, this is all they see happening. Before we even get to the point of programming your car, much has already occurred. In some cases, months of development has taken place to finalise a product. In the case of the Mazda MPS range, almost 4 months of time was invested in testing and R&D. Consider too, this development is done using expensive test equipment, dynos, software, dataloggers and computers.
9. Does flashtuning need to be done on a dyno?
In most cases, no. Flash tunes are designed to be safe across a model range. Much time, money and testing is invested into creating a flash tune. You can be sure it is suitable. If you have an extreme set of modifications, we would advise dynotuning.
10. Why do you not list exact specifications?
The issue of exactly what parameters are altered, and to what value, is often beaten to death on car forums. People and companies are sometimes accused of withholding information, being dishonest, lying and even incompetent. All of which are furthest from the truth. Exact specifications are not often released as this is proprietary information. Especially when in a developmental phase. It is commercially sensitive information. So from this perspective almost no Tuner will give you exact specifications. Only ballpark. This is a common occurrence, and not unusual. We all wish to protect the information, knowledge and files we have all worked very hard to develop. Just like any other company trying to protect its proprietary knowledge and information.
11. Will a tune damage my car?
As with all modding, there is always that chance. The risk is no more or less than any high performance modification. And it also depends on how radically you drive. It is also extremely important your car is in perfect running order before tuning. High performance tuning will not fix problems, it will more than likely exaggerate them. We have tests that can check your car, and report to you if we can see potential problems. You will be advised of potential issues before any work is performed.[/B]
Original Link: http://www.dptune.com/dpt_014.htm
