Quote:
Originally Posted by tomm.brz
you make it look like there is only one particular "engine load" curve to have, but to me that s not the case.. changing the maf or the speed density will of corse change the engine load values, but you can just adapt to it and adapt the tables accordigly
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I totally agree with you that there isn't just one perfect "engine load" curve we should aim for.
What I'm saying is that I don't believe that rescaling the MAF is actually "changing the load" in a negative way. I.E. we're not trying to fool the ECU with false data, but instead using the AFR feedback from the O2 sensors (via the LTFT's) to ensure that we're feeding the CORRECT airflow data to the load calculation. MAF Scaling done properly is ultimately a sensor calibration, nothing more.
Yes, it would mean that you end up in a higher or lower load cell on the other critical maps for a given MAF voltage, but you are ending up in the RIGHT cell because the correct amount of measured airflow is being used to calculate that load. The old load value was wrong, because the sensor was not calibrated correctly.
Now, it's kind of a simplistic example, but think of it like having a thermometer that only reads 90 degrees C / 190.8 degrees F when water boils at sea level. If you recalibrate the thermometer so that it correctly reads 100 degrees C / 212 degrees F when the water boils, you haven't changed the temperature of the water, you've just made the tool you use to measure the temperature more accurate, so if you specifically need 80 degrees C water for some reason, you can have more confidence that the thermometer is giving you the right info.
Sure, MAF Scaling *could* be used like the example I gave of the piggyback fuel tuners to intentionally feed false, higher airflow numbers to the ECU, but because we are able to work directly in the tables to set AFR targets, etc. and we have the feedback of the O2 sensors to see how close we are, there's no need to use such a crude method.
Again, this is all presuming that Subaru's calculations behind the scenes are correct RE: the injector opening time / pulse width needed to achieve the target AFR for each load / rpm. Since those aren't something we can edit, we just have to work with them as-is.
