Desired torque implications on tuning process
Posted: June 12th, 2022, 4:38 pm
Hi all, I'm currently trying to understand how the Desired Torque table works.
Can anyone confirm if this is how the calculations are applied? Looking at the table axes, this is the only flow I can think of that makes sense.
IRL APP -> Throttle Duty table = "Requested" Throttle Position (degrees)
"Requested" Throttle Position -> Desired Engine Torque table = Virtual "torque" [and this is an abstract value, not calculated using any sort of closed loop calculation etc, simply used as an index in the next lookup?]
Virtual "torque" -> Relative Throttle Plate Position table = Actual Throttle Position
I'm assuming changing the Desired Engine Torque table has no impact on fuelling or ignition on its own, but is just used as an index for other tables?
How does the Calculated Engine Torque table affect things? Is it a cruise-control thing, considering there is no APP or TPS in the axis?
Assuming this is the case, assuming I had the time to spare, to do a full tune to the best of my ability, would it make the most sense to (ignoring ignition timing tuning for the minute):
1. disable closed loop (zero the Closed Loop Max RPM value)
2. modify the Throttle Duty table to ease-in to linear (similar to stock)
3. Flatten the Desired Engine Torque table values to be linear (from 0 to x, x can be whatever)
4. Modify the Relative Throttle Plate position table axis to be from 0 to x as set in the Desired Engine Torque table and set the values to be linear from 0 to 84
5. Set a flat AFR in the AFR table (eg. 13.8 or 12.5) for tuning purposes
6. Tune using the VE table to make the actual AFR match the intended AFR as close as possible
EDIT: as Walle has pointed out, it may be more effective to utilise the trims + the actual AFR, rather than use the possibly erroneous "target AFR" value. There is also no requirement to do step #5, however I would personally just to make the math easy.
EDIT 20230110: actually using trims is probably not a good idea as it targets 14.7-15.2 (based on the Closed Loop offset table) which isn't safe for high load. Honestly I'd suggest setting a flat AFR across the board in the AFR tables, then comparing the actual AFR to whatever you're aiming for. Then use and use that to multiply into your VE table
After that process is over, the AFRs can be tweaked in the AFR table to go for maximum power as usual.
Steps 3 and 4 should effectively disable the Desired Engine Torque table if my understanding is correct to reduce the variables at play, making the TPS correlate to the APP as specified in the Throttle Duty table?
EDIT 20230110: yes as per my thread here it is safe to make the desired torque and throttle plate position tables linear as long as calculated load is updated too. I haven't tried it without updating calculated load.
Can anyone confirm if this is how the calculations are applied? Looking at the table axes, this is the only flow I can think of that makes sense.
IRL APP -> Throttle Duty table = "Requested" Throttle Position (degrees)
"Requested" Throttle Position -> Desired Engine Torque table = Virtual "torque" [and this is an abstract value, not calculated using any sort of closed loop calculation etc, simply used as an index in the next lookup?]
Virtual "torque" -> Relative Throttle Plate Position table = Actual Throttle Position
I'm assuming changing the Desired Engine Torque table has no impact on fuelling or ignition on its own, but is just used as an index for other tables?
How does the Calculated Engine Torque table affect things? Is it a cruise-control thing, considering there is no APP or TPS in the axis?
Assuming this is the case, assuming I had the time to spare, to do a full tune to the best of my ability, would it make the most sense to (ignoring ignition timing tuning for the minute):
1. disable closed loop (zero the Closed Loop Max RPM value)
2. modify the Throttle Duty table to ease-in to linear (similar to stock)
3. Flatten the Desired Engine Torque table values to be linear (from 0 to x, x can be whatever)
4. Modify the Relative Throttle Plate position table axis to be from 0 to x as set in the Desired Engine Torque table and set the values to be linear from 0 to 84
5. Set a flat AFR in the AFR table (eg. 13.8 or 12.5) for tuning purposes
6. Tune using the VE table to make the actual AFR match the intended AFR as close as possible
EDIT: as Walle has pointed out, it may be more effective to utilise the trims + the actual AFR, rather than use the possibly erroneous "target AFR" value. There is also no requirement to do step #5, however I would personally just to make the math easy.
EDIT 20230110: actually using trims is probably not a good idea as it targets 14.7-15.2 (based on the Closed Loop offset table) which isn't safe for high load. Honestly I'd suggest setting a flat AFR across the board in the AFR tables, then comparing the actual AFR to whatever you're aiming for. Then use
Code: Select all
ActualAFR/TargetAFR = multiplierAfter that process is over, the AFRs can be tweaked in the AFR table to go for maximum power as usual.
Steps 3 and 4 should effectively disable the Desired Engine Torque table if my understanding is correct to reduce the variables at play, making the TPS correlate to the APP as specified in the Throttle Duty table?
EDIT 20230110: yes as per my thread here it is safe to make the desired torque and throttle plate position tables linear as long as calculated load is updated too. I haven't tried it without updating calculated load.
