Hello guys,

These days, a friend came to me with a request to change his already remapped file for more power at low revs. The map was made two months ago in famous tuning company in our country. After I reed the file and looked at it, I was amazed as I saw changes. All the things are totally different from everything I've read in this forum and I have no explanation why it's done in this way.

The car is Audi A3 1.8T AQA 150hp quattro 1999 - 06A906032CB 0261206434 350716 - 512kB 29F400 flash

The following upgrades were made to the car: Turbo K04-23 + Audi S3 injectors + Audi S3 MAF Housing.

Can anyone explain to me how you can go to bigger MAF Housing and do not rescale MLHFM, or put bigger injectors and increase KRKTE instead to decrease it, or put values like requested lambda 1.3 in KFLBTS @190 load @ 6000RPM  :0

I think this is a quick way to take the client's money but how does all this nonsense changes work?

Honestly, you are the biggest spammer I know!
No benefit of your comments. Please skip my topics.

Hey Adam, how this shit works?

Not the Answer you wanted, but maybe I can help you with an example of experience i made in other business fields. I can't tell you anything about your file as i have little to zero knowledge in engine tuning.

Let's suppose Company A buys a software that transforms input data x to output data y. The Software was programmed by a professional company B. With the completion of the program, responsibility for maintaining the Software was given to the IT-Department of Company A.

Every two months, the structure of data x within Company A changes. So the software must be fitted to handle the data x to get the same output y. There are several types of IT-Guys, and with them, their coding style changes:

IT-Guy 1: He has no idea what he is doing but he is tweaking the program with try&error until result y looks like it should be. He benefits from the fact, that some variables in the software have names that sounds promising and he changes them until everything works.
IT-Guy 2: Is a professional programmer and changes the whole program with lots of effort to make his code efficient and understandable for anyone else.
IT-Guy 3: Lazy but clever: Compared to Guy 1 he knows exactly how the programm works and how he can change it with less effort as possible to make it calculate y right again. For his objective, he sometimes uses function parts in a way they were not designed for.
IT-Guy 4: Writes unreadable Code on purpose to confuse others. From my knowledge, this often happens in security software to prevent hackers from understanding the program workflow after disassembling.

Do some Logs and you will see, if the tuning company's soft produces the right "output y" for your customer. Then you probably have a clue what happened there.

The mostly reason for underscaling is the internal load limit inside the ecu, there are lot of people doing this
Myself had to do this too few times, because when you try to adapt fueling correctly for bigger injectors this won´t work really well on some software-versions

The easiest way for most people is reducing maximum measured load with a bigger maf-housing.
Then they tweak fuel until the afr fits.

The bad part of this is esp/abs and pedal-response might will work spooky, because the real load is significant higher then ecu thinks it is

I get what he is saying (but maybe he meant ps_w)

In any case, you can avoid changing MLFHFM and KRKTE by choosing the right combination of non-stock maf and non stock injector/fpr such that their scaling cancels each other out  (for the purposes of fueling anyway).

If you're insanely lucky the car will run right. But generally, nobody is that lucky, and if you run a MAF too much underscaled, you'll have all sorts of side effects because load is way the fuck off.

In any case, we can all agree the OP's file is shit.