Total airmass ingested is *completely* described by MAF readings.

VE for fueling is only relevant when using speed density.

KFMIRL - target load from torque/rpm. The torque input is far from driver's request.

KFMIOP - optimal torque from load/rpm. Not sure who made up the whole VE angle of this map, but Tapp didn't make up the title, Bosch did. The output is torque and just like optimal ignition angle it is almost exclusively used in intervention.

I do like your positive attitude, but you keep writing the same story without relating anything specific to this map.

I appreciate you guys for being open minded and not turning this into a pissing match. Here is the general idea. I don't believe that MAF reading is the only Airmass input until the MAF is unplugged. I believe the optimal torque map is put in place to check MAF readings and compare them. Based on fuel trims derived from 02 correction, timing, and boost to effect the Actual torque produced by the car without the driver feeling the ill effects of air density, driving load and intake temps on power output.



You, the driver, press the accelerator pedal in accordance to your wish.

This variable will be known as Pedal % and it is the X axis of the Accelerator pedal map.

Pedal % is then matched up with RPM on the Accelerator pedal map

the value in this cell becomes the variable Driver's wish

Driver's wish is then exported to the Y axis of the Target filling map

Driver's wish is then matched up again with RPM on the Target filling map

the value in this cell is the "raw target load" (which I think is in relation to the kpa translation from MAP voltage) we will call it Raw load

*Raw load is a value we do NOT see, it is NOT engine spec load (that is merely the value you can set for the max VE on the boost tables and is there to limit overboost situations) *

Actual Load is measured by the MAF, or calculated by ecu in the case of MAFless or malfunctioning MAF and exported to the Y axis of Optimal torque map

Actual Load is then matched up with RPM on the Optimal torque map

This variable is Optimal torque

Optimal torque should, if the mixture is at 14.7 or 1 lambda, match up correctly with the percentage of torque that is required to keep the car moving in accordance with the target filling map. Once we can see the actual torque put out by the engine in the data this will be easier to see. if it doesn't the car will begin to make fuel and timing changes to try and get that in line.


so as you can see if you change the target filling maps you can get the new optimal torque values by doing some math on the values of the target filling table.

After going through all this I am really beginning to see how tuning a MAFless car would be MUCH easier following Maestro 7 style of tuning with the full load lambda map etc, as oppose to my file using solely the power enrichment.

This theory also explains why when people unplug a bad MAF the car runs a lot better when the car is on a stock tune. Unplugging the MAF triggers the alpha-N tables and airflow over tb, etc etc.

Since these tables are pretty well dialed in from the factory for the factory tune they are much better values to use then a low reading MAF, so the car runs better because torque control isn't limiting power because it's seeing low MAF readings meaning Driver's wish and Optimal Torque aren't matching up

In order for the ECU to know whether or not the it needs to make the engine produce more or less torque in order to comply with drivers demand of current Load(value measured by MAF or calculated if running mafless), it needs a value to check against. This is the value you are adjusting on the optimal torque map.

Now since the optimal torque map effects many variables off a single value, it is safe to assume that you can adjust for 02 correction and know that the effect of requested boost and timing from the optimal torque map will also be in line and if you have problems in these areas after getting fueling set you need to begin to adjust other maps to affect those values.

I don't think the ECU makes fueling changes to bring output torque in line. Why should it, when it can use throttle plate, requested boost, or timing, to do that?

Again, are you saying IOP

1) alters requested AFR
2) can help bring actual closer in line with requested during open loop
3) is used as a feed-forward component in closed loop

Your wrong. The MAF reading is used all the time (that it is plugged in and passes diagnosis). When the MAF fails diagnosis or is unplugged then load is calculated from TPS. the ECU NEVER switch's  between the two when the MAF is plausible.

Thank you for the time and effort spent in this.

In reviewing my logs, the torque intervention events (that aren't ARM) seem to co-incide with mifi or mimax being too high in MDKOG, which, as you said, are unrelated to load being too high.

When load (or MAF) is too high, I get fueling problems, not timing intervention.

This calculation uses the *optimum torque* table as a starting point.


IMO it is compared to misol, which *isn't* from the optimum torque table. Again, i think the "actual" torque is calculated using the IOP as a starting point.

I could be wrong on this, it is from memory and I dont have the FR handy to check.