pokeybritches wrote: ↑Sat Nov 18, 2017 9:23 pm
The issue is the tools to tune the ECU are outrageously expensive.
Injectors are easy to account for, once you have those tools. The injectors should have come with a matrix of values that are plugged into the tuned file.
The adjustments needed for the modified intake system are different and require a bit of tweaking. The transfer function for the MAF sensor can be figured out with a bit of trial and error (if you’ve modified the intake system at all, which you have in this case, then the transfer function changes... even if it is the same MAF sensor). You can probably get away with not tweaking the transfer function on your car, but it will only give you a tune that’s “close” and not optimal.
Most tuners don’t mess with the factory tables for part throttle / closed loop values, because once the injector values and intake is accounted for, the fuel trims are pretty close. Tuners extend the WOT / open loop maps and make their adjustments there. You’ll either need a data logger or dyno in addition to the software to edit the fuel maps.
To get the fuel maps, software companies decrypt the ECU and find patterns to determine fuel maps. These files are sold to tuners, who then make their tweaks (meaning there’s a cost involved, even if you do the tuning yourself). No one to my knowledge has cracked the MS45.0 DME and offered the ability to modify fuel tables via open source source software.
A dyno is preferable to have when you adjust the fuel tables. AFR, timing, Vanos adjustment, etc. are kinda up to the tuner, but there are standard techniques you can employ to get a solid, safe tune.
Even if you input the injector tables, modify the transfer function for the intake system and MAF, and get your open loop fuel tables right, you still need the software to remove things like the torque limiter that’s buried in the programming of the DME.
TLDR: Pay a reputable tuner, and not someone that offers a generic flash with slightly altered fuel tables for an otherwise standard car. When my supercharged Z4 was modified beyond the standard VF kit, the tuner had to build the files from scratch... which took days for a pro with his own personal dyno. My advice is to not try to tune it yourself, because the necessary tools are beyond the scope of your project.