You need to tweek inverse fuel density on BGKV... but to be true I didn´t found on your file...

In the newer ones you have a value to tweak...  TANKL didn´t change anything for me (by the way, it´s the same value in file for Punto or Bravo thar have diferent tanks)

Something is seriously wrong with knock detection, either on my particular car, or on this setup / ECU in general. Just replaced the knock sensor (brand, Bosch), torqued it to spec. I still get excessive retards, on E68!!!. (No, I have not gotten time to take out my knock monitoring gadget). There is actually some weird faint rattling-like noise coming from underneath the car, but it's also there when I stroll very gently through the neighbourhood, will have problems locating it. The only thing I can think of that is out of ordinary - we have a frying plate over here for almost a week, the air is dry, and my IATs were between 40-45 today (at 19:00). I even got a slight retard on one of the cylinders at light acceleration, low RPM, load at ~100%. WTF?

I'm just shooting blind.
But could the AFR drop be caused by knock if your fueling via LAMBTS.
There is a knock reactive delta fuel map (KFFLBTS?)

Then again, I could be completely off target.
Just a little brainfart.

I did some unstructured tests, had to fill up in the meantime and went from E67 to E75 mixture. Nevertheless, I think I am getting there (BTW, much cooler this evening, lower IATs than before, ~35C). Changing the knock frequency configuration from another bin quoted above does not seem to change much or anything (I purposely left the stock rich fuel not to change to many things at the same time). Still knock retards, a bit less than before, but still on 2-3 cylinders.

With less fuel, both on E67 and E75, I saw an improvement - retard still there, but only on one cylinder and not going below -4.5. I manipulated my AFR requests to be around ~12.0, the actual is more like 11.5 according to post cat Zeitronix, this has to be the impreciseness of the speed density thing on this ECU. The mean retard is low enough not to cause flooding through DLBTS.

So this seems to be it, but I have to test more and dare to drop the fuel still a bit more on E85. Also, with the dropped AFRs the car felt less choked and more consistent.

All this ought to be done on a dyno and ignition should be tuned in for E85 too, but I won't have time to do it any time soon. I also feel uneasy doing this without EGT, but oh well...

Oh, and BTW, TANKL indeed does not seem to do anything in terms of reserve light on the dash. In fact, I got a low fuel warning message on the dash with a beep (due to range below 50km) and no reserve light at the same time. But at least my fuel consumption figures are correct now, and range is correctly calculated.

Yes, I know that, I messed with the frequency just for one test, the knock sensor is changed, no results.

The car is seriously overfueled by factory (there are moments in my logs where I see 9.7 AFR request mid RPM range), the more I look at all this, the more I come to the conclusion that this ECU should be calibrated from square one. I also now know why my AFR drift away downwards from targets on E75, FKKVS is not factory calibrated beyond 20ms (actually, anywhere beyond stock operation range) and stuck at 1.0, while most of other high load cells are 1-5% reduced.

Once I fully confirm my ethanol knock is caused by fuel, I will have to make a plan how to methodically fix all this, for both fuels.

It is time for me to do some homework. The retards kick in almost unconditionally on full throttle, 0.5-1.0 second after the actual load reaches requested, never before that (in my logs, which are not that thorough), even on already high load. Seems almost as if this is done as precaution, which makes me think I have to look into the adaptation conditions and algorithm for knock, found a nicely translated KRRA module description on the wiki here. Resetting adaptation parameters on the ECU probably won't hurt either. I have only one spot in one E67 log where on full throttle during half-pull the retards are zero, one! I looked very very carefully at that spot and cannot find a differentiating factor. I also know that overfueling is not it - have one spot with mild fueling (13.5 to 12.0 actual) in the logs where there is still retard.

As for the external noise - the only thing I can think of is rough road surface here. The mid axle joint mount from the right wheel is bolted directly to the lower part of the engine block under the knock sensor. And all the roads are rough and noisy, almost no exceptions.

I am not going to argue with that, nevertheless, I want to understand what values and patterns to expect so that I know what I am looking for (especially that my knock sensing education is only now starting to build up).

To start with that, I logged the knock sensor voltages and tried to map them with the other running parameters. (Putting aside if I got the conversion for the voltage right, the documentation and sources are messy and inconsistent about this). I see two things - knock retardation comes more happily when the rpms ramp up quicker (probably normal), and the voltage pattern follows almost precisely the RPM line, see the pictures. I have three spots there when there is a retard, the first is mild load (~110%), two others are high load (190-160%).

Is that normal (again, looking at RKRMX maps, probably expected)? Or should I now be looking at engine speed related interference (valves?)? Or perhaps an electrical issue of some kind, like bad shielding / poor ground? Or, perhaps, is the whole system simply too sensitive? (not sure if what I show gives any grounds to establish that)?

Otherwise, yes I got it by now , something could be loosely screwed and resonating along with rpms. Will look for that when I have a chance.