xtyper

I have a question for all you tuning gurus out there, and that is, how exactly is a tune file created?

In the case of starting from a fresh stock ECU, the typical process involves mailing the physical ECU off to a vendor. They then crack it open and read out the stock map. Now what? Does the tuner then open that stock file in a program and then go through all the individual maps to manually alter the tunable parameters? If so, how does the tuner ensure that they do this consistently every time, and don't miss any maps in the process, or worse yet, accidentally change something they shouldn't have. In other words, if a 100 of us send in our stock ECUs to one particular tuner for their "shelf map", what ensures that all 100 of us will end up with the EXACT same tuned file at the end? Or is the stock to tuned file transformation less a manual process and rather involve a more automated complete file overwrite where my concerns would not apply?

Just curious how the process works and how customers are ensured a consistent product.

propain

Its a file replacement. The changes are made and they upload the new file which replaces the old file. This is why the last discussion about partial tunes had such contention.

There are tools available to make changes to the file on the fly though from what I hear. There are very few and tightly guarded by MB.

ZephyrAMG

Good question. Also, does it change the opening of the throttle bodies or that a physical replacement change that has to happen...?

xtyper

If it's a full file replacement, then why do the tuning "middle men" always need to first read out our stock file and then email it off to the tuner to get updated, then sent back and reloaded to the ECU?

propain

Not sure of the process exactly, but the ECU needs to be cracked first before the file can be uploaded onto it.

If a dealer flashes the ECU back to stock the ECU can no longer be tuned via the ODBII port and needs to be cracked again. If you had a block tuner and the dealer flashed you back to stock it would no longer work and you would need to send your ECU back to be cracked again.


Thats my understanding of the process.

xtyper

Thanks Jim, and while that is helpful information, I still don't think it definitively answers the question about how the tuned parameters are actually loaded. I'm hoping one of the tuners chimes in here with some first hand knowledge.

propain

Not sure what your looking for then. A laptop and a file are how the paramenters are loaded onto the ECU.

Im sure a tuner can better explain... but without giving away their process I dont think you will get much more than that.

BerBer63

i don't get what you're wanting to know...they load a new file (1) onto the ecu with all the different throttle maps, parameters, 1/0s, etcs

novae500

Here is what my tuner told me when i got just a tune and asked how did the tuning work. There are about 80 or so parameters that can be changed. He doesnt change all 80, but certain ones that make the TB open more than what the stock ecu file would have, air/fuel tweaks, speed delimiter, etc. He does leave the safeguards in place that MB has, so if a vacuum line or whatever fails, the stock ECU from MB "shuts" down and doesnt let the engine go kaboom. Those parameters he doesnt disable.

He took his laptop and plugged it into the OBD II connector to get a reading to make sure the laptop can read the ECU. After a few tests, the upload/download of file begins. Less than 5mins its done.

xtyper

My question simply boils down to this. If I'm a tuner and you ask me to tune your stock ECU, do I have to open your entire stock file in a program, go hunt for all the parameters that needed adjusting and manually change them, then resave this adjusted file as your new tune file, and finally reupload to the car? Or do I simply open your stock file in a program, flash a new tuned file in its entirety over the entire stock file that I already have ready and verified to be correct? Clearly one method over the other leaves much less room for error and ensures a consistent product every time.

Put another way for all you Excel users, am I simply copy pasting a new tune file over your entire stock file? Or rather having to open your stock file and manually go through all the cells that need changing, change them, and then resave the file as your new tune file?

BerBer63

They do the latter. They open up your ECU, plug it in with that machine, upload a new file over the stock/previous file and finished.

They can also download the previous file, which I'm sure some tuners do or have done in the past, but that's a different story. They don't change the parameters in the stock file (they may have done that initially to create their 1st own Tuner file, but now they just upload whatever off the shelf file they have.

propain

Didnt I already answer that in my first reply to you.

xtyper

Wasn't quite sure if that's what you were suggesting. Either way, nothing wrong with seeking a second opinion.