The Driver Demand Torque table is MUCH lower than the Torque Model table on this factory tune (Ford Controls Pack). Somewhere around 20% at the high end. Is this limiting torque / power at WOT? Sorry, may be a dumb question...
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The Driver Demand Torque table is MUCH lower than the Torque Model table on this factory tune (Ford Controls Pack). Somewhere around 20% at the high end. Is this limiting torque / power at WOT? Sorry, may be a dumb question...
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Last edited by lee82; 08-19-2021 at 11:05 AM.
Its not a dumb question, but its not a simple "yes it is" or "no it isn't" answer. You need to log all PIDs that have the word "source" in them and see if you are hitting any limits. That's the easiest thing to do to answer your question.
The torque model shows a load to torque relationship at Stoich AFR, MBT Spark, and other standard conditions (like in cylinder air and coolant temperatures). Its just like a dyno's correction factor, with the idea being: given temperature and elevation differences, the MAF and RPM sensor readings relationship of load will always produce the same indicated torque number. It just goes a bit further than a dyno with the number of parameters it standardizes for.
The ECU takes all the actual conditions into account and estimates what it thinks the engine brake torque is. The driver demand table should agree with this estimated torque value to avoid any torque errors or at least minimize them. This is matching your throttle body blade angle to your accelerator pedal by airflow, through the standardized load to torque model.
There are defined limits in the tables, some referring to the modeled torque and others referring to the engine brake toque estimate. Then you have lambda limits and spark limits and a bunch of others. Those would just need to be found and increased, usually done by monitoring what your source PIDs are saying.
You can do things like skew the inverse relationship of the torque model to get around undefined limits or to follow tuning strategies like "keep the driver demand table stock", but this gets convoluted.
Last edited by murfie; 08-21-2021 at 12:13 AM.
Thanks for the explanation!
Doesnt the mustang ignore torque demand and go wide open over about 80% throttle? Thats what the hptuners description says anyway. Its under airflow->ETC->WOT if I recall correctly.
Depends on WOT start and end values. Even if it ignores it, it still has to place a torque value to the electronic throttle position and airflow in the event the ECU needs to take over torque request, and that usually reflects what is in the driver demand table(whether it is accurate or not). It just doesn't closed loop correct it to the estimated engine torque, so if you are above WOT start, more pedal might not increase torque output, less pedal might not decrease torque output.
I had a related issue where, in my opinion, torque demand was set too far above indicated torque at wot. I’m not sure if it caused an odd intermittent traction control issue I was having, but for sure it affected how quickly it cut throttle when “pedaling”. This actually could create a dangerous situation…
Interesting about the traction control. I am using a FRPP crate ECU that has no traction control, ABS, no VSS, etc. The only strange thing I've ever had was some odd surging during part throttle acceleration. I also get VERY low timing advance during idle too. Sometimes negative.Originally Posted by engineermike
It uses spark advance to control idle speed. You might try lowering torque demand at idle to get the throttle blade to close some, which would force the timing higher. Mine runs pretty low at idle too, below 5 iirc.
I use a simple method to decide if my tune is limiting my power: spark, lambda and throttle position. If each of those 3 are where I expect them to be then don’t see how the tune is pulling power. If one of them is off, then I have to figure out what is limiting me.
Guess you could throw cam position into the mix, but that’s hasn’t caused me issues in the past.
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