700 mbar is insanely huge. That is a bad sign.

Forgot that the forum isnt letting me attach .csv files.

Here is a .zip with the current tune and a datalog.

Note the MAF scaling used for an audi v8 MAF and also the ps_w/pvdkds_w deviation

KRKTE was calculated at .030xx and is at .027xx in the attached file.

Fuel pressure is 50psi measured with a gauge using a 3.5bar FPR


My tuning philosophy would be to use the calculated KRKTE/TVUB values and see where things are at, then scale MLHM to get WOT fueling as close as possible. However, doing this on either a stock or 5120 file produces the issue with ps_w you can see in the above log.

Scaling MLHFM down as per the wiki seems to be the go to solution for ps_w>pvdkds_w. Should I be looking at KFURL/KFPRG instead?

The above log has the stock MLHFM from a 4.2L file and given that it will read slightly too high because of the filter location in relation to the sensor, it is probably reading a bit higher than actual. I just verified that there were no boost leaks, but the silicone hose on the turbo inlet was a bit loose.  Same issues as before in regards to both ps_w and lean spiking. I'm running out of ideas here and its difficult to do any troubleshooting because the car is 1000 miles away
 

Figured I would this just because there were unanswered questions and it may help somebody in the future.

Issues with ps_w were fixed by playing with the VE model. I had to scale KFURL mostly, and a tiny bit of changes to KFPRG at idle. From my understanding, KFURL is part of the calculation that the ECU does when calculating for fueling. Its output is a scaling factor using inputs of differential manifold pressure (MAP - ambient) and RPM. It was scaled roughly to match the % difference in airflow at a given pressure for the new turbo vs stock turbo. Scaling was heavier in the higher RPM regions due to the low efficiency of the k03. I then used my histogram tracer tool and used (pvdkds_w - ps_w)/pvdkds_w as a scaling factor and logged those variables along with RPM to further refine the scaling. ps_w came down nicely, and follows pvdkds_w nicely. It isn't perfect, and ps_w is sometimes up to 200mbar in excess of pvdkds_w but it is much better than before, and fueling looks good up to 35psi on the 5120 hack.

And had normal calibration of the MAF scale and its correction map worked properly or made any difference in logged values, thats where I would have quit. But it made zero difference on ps_w with MASSIVE changes. Fuel pressure was measured with multiple gauges, KRKTE was calculated properly, and scaling MLHFM down incrementally to under 1400kg/hr @ 5v (~2000kg/hr stock) made zero and I mean ZERO difference to ps_w. The only change I saw from scaling the maf curve, or introducing corrections to KFKHFM was leaner WBO2 measurements/higher lambda sensor correction. This was on a standard tune as well as a 5120 tune. Huge excess in ps_w on every single log I took. The first tune with KFURL alteration of about 15% brought ps_w into the realm of reality and fixed most of the WOT fueling issues. From there, the stock 4.2 MLHFM and a few passes over KFKHFM took care of the rest.

As stated, it is imperfect, but leaps and bounds closer than it has been since I began this project from a stock base file on an already complete build. I know this isn't the first time you have addressed the "You shouldn't have to touch KFURL/KFPRG" topic. I've seen you make that claim a couple of times in a couple off threads, but from everything I can tell, it seemed to be necessary in my case for whatever reason. Something was very wrong with the ps_w calculation and it wasn't 5120 related. This is the only thing that made a difference  

That said, I always try to do things the right way. I made every effort to correct things the way they are typically handled and using maps the way they are intended to be used (except for FKKVS  ). If I'm somehow overlooking something or there was a better way to accomplish the same task, I'm open to suggestions. The only other thing I could think of would be a hardware difference between the original fried ECU and its replacement