Tuning AVCS without a dyno (AVCS for Gruppe-S header post 12 and 24)

[Compelica]

@Kodename47 coming back to this again...

For the WOT Best VVT calculation this was mentioned in the wiki:

VVT System #1 (Note: Use a log parameter that replicate the VVT table values, this may be different to actual VVT angle dependent on the system.

I'm trying to understand the reason why you would use commanded values instead of actual values... I would think that it was intended for more consistency, and to remove overshoot or values a distance from targets.

Thing is none of the current Tactrix log files are able to log the commanded AVCS, you could use OBD2 PIDs but the capture speed probably isn't enough. I did a comparison, feeding actual and commanded values (created a new column to to put table values where RPM and load is concerned) and there isn't a major difference; mostly the same on midrange but +5/-5 degs away at redline.

[Compelica]

Did a few runs on the exhaust AVCS with a -8, -4, 0, +4 and +8 and fed the results back to the tune. Naturally the optimum angles were peaky and wavy so I attempted to smooth out between peaks, with the system tracking rather well.

Despite running with -1 timing and without LTFT (my LTFTs are typically 2-3%) my typical knock at 5k RPM and at redline was eliminated so it looks like a good start.

https://datazap.me/u/compelica/vvt-i...zoom=4746-4876



For testing purposes I then loaded the unsmoothened exhaust angles as per VGI results and while the AVCS system could still track targets I would start to get knock at the rapid dips of the exhaust VVT movement. This was running at full KCA though.

https://datazap.me/u/compelica/intak...zoom=3448-3872

[NicFromTheNorth]

In the above logs the engine load varies very smoothly compared to the MAF voltage, especially at low RPM and wide open throttle. With what device do you log? Or did you manually filter the engine load?

[Compelica]

Originally Posted by NicFromTheNorth

In the above logs the engine load varies very smoothly compared to the MAF voltage, especially at low RPM and wide open throttle. With what device do you log? Or did you manually filter the engine load?

No filters - I'm using Tactrix to log.