C7 Procharged Pulling all timing around 6200

[bad383ta]

I installed a Procharger on a 2018 C7 A8 Grandsport. The car runs great and makes good power 585 rwhp on 7.5 pounds. However on every run all the timing is pulled around 6200-6400 rpms. The logs are showing me its knock retard, I have verified its not removing timing for any other reason that I can log. Its not pulling for torque management. I have max knock retard set at 16 degrees and within 100-200 rpms it will pull every last degree it can at 6200-6400. I have done so many pulls and tried so many things that once i was convinced that it was false knock, i set max knock retard at 0 degrees made a pull with zero issues all the way to 660 and made 604 rwhp. Im commanding a 12.20 AFR but have tried everything from 11.5 to 13.5 without a change. I have lowered timing as far down as 4 degrees in those rpm ranges all the way up to 16 degrees and it makes no change just pulls all the max allowed timing that im giving it. Im hitting no limiter that I can see, fuel pressure is dropping a few hundred psi, I have played with injection timing and VVT. During multiple pulls i may get a degree or two of spark nock in different rpm areas but at 6200-6400 it just all gets pulled no matter what. I even set the knock sensor multipliers as high as 6 and still pulled all 16 degrees in the rpm range, actually up to 18 on some pulls . Someone please check out the attached tune and two logs, I'm dying trying to figure this out and its probably something simple. I have included the calibration to look over and two different datalogs with different things mointored.

Thank You
Bad383TA

[Higgs Boson]

two things, have you edited your Virtual torque model under the drop down menu, Edit?

the ecm will pull spark when you are out of fuel, what is your injector pulse width?

[bad383ta]

Higgs, I have not edited my Virtual torque model and yes the cars out of fuel, pw in the 6-6.5ms time. My afr is 12.2-12.3 across the board and my fuel pressure is 2100-1870 at the top of the run. I know it will pull some timing but 16-18 degrees of it? Its just a stock c7 with 7.5 pounds.

Bad383ta

[bad383ta]

Higgs, Thank you. I started playing with the Virtual Torque Model and wouldn't you know it, on my last two pulls I was able to pull the car 300-400 rpms higher. I have been logging torque management timing and have never seen anything pulled, so I was not looking at a torque issue for the timing. It Just reinforcing how important it is to have a correct torque model.

Bad383TA

[Gibspeed3]

A year old thread, I know, but I'm chasing the exact issue on an ATS with a big turbo. Approaching 6500 rpm the ecu with immediately pull max allowed KR, every time, no matter the base advance. This car is also on full E85, so we'd normally be way out of fuel, but we're using aux injectors to pick up where the DI leaves off. Absolutely zero issues below 6500rpm.

What were you seeing with the virt tq? And did you end up needing to lower it or raise it in the affected area?

[Ben Charles]

If you open the VT editor and then expand from 800 to around 1800 (1.8 cylinder load) it becomes apparent the factory VT table is flawed

This is very important for trans tuning and reported Tq load as well

[mbray01]

ALSO HAD ONE THE OTHER DAY, HAD A TIMING PULL AT 6100 THAT WAS DRIVING ME CRAZY. A.C WAS ON, AND EVERY SINGLE PULL AT EXACTLY 6100 IT PULLED TIMING FOR 100 RPMS THEN RIGHT BACK. i NEVER HAVE A/C ON , ON THE DYNO, BUT THIS TIME I FORGOT TO TURN IT OFF. lESSON LEARNED, BUT YES, MAKE SURE THE A/C IS OFF

[sevinn]

Yup, it's a frustrating thing to fight. If you are street tuning it only comes out in the first gear of the pull withe the AC as well.