2015 Mustang struggling with Torque Control spark cut

[Plimmer]

I'm struggling with torque control cutting spark during a pull through the gears. See the 2nd to 4th gear log where in 3rd and 4th torque control cuts spark to 20 degrees.

Intake is a GT350 with GT350 TB and exhaust is Stainless Work catless headers and 3" system. I've tried everything and I'm ready to give up, I've tried stock driver demand tables with stock torque tables, no luck, modified driver demand tables and stock torque tables, no luck, modified torque tables, no luck.

What am I missing here? Any advice appreciated, thanks


v2.3e 2nd to 4th gear.hpl
v2.3e 3rd gear.hpl
2015 Mustang Map v2.3e e85.hpt

[HPF]

hey
raise the "maximum torque" 1&2 to 800 lb ft and tell us if its gone after

[murfie]

What HPF said may help. I am guessing torque 1 and 2 refer to torque at which spark and ETC cut.

If you take your ETC TQ request and divided it by the engine brake torque you get the torque ratio. Notice that if the request is higher than the engine torque the ratio will be larger than 1 and if its less it will be less than 1. The Fuel cut torque ratio is only used when ETC is less than engine torque(ratio less than 1) as you don't want it to cut fuel and cause a lean condition when the engine is being requested to make more power. That's why it can only cut fuel below a 1 ratio. Coyote cook book says to raise this to 1 but does not explain why. Above 1 it uses spark and ETC to limit torque. Also notice the spark only torque ratio is used when ever the ratio is above 0. So it can cut spark any time the engine is not in DFCO basically. Anywhere between 0 and 1 it can use one of the three it sees fit or a combination.

I looked through your log and see at WOT your torque ratio is .85 to .99. If you don't want to risk a fuel cut at WOT I would suggest lowering your fuel cut torque ratio for DD to less than this not to low or you will get spark and ETC rather than fuel cuts. If you want it to stop pulling spark you need to raise the spark only torque ratio above .99. Or you can manipulate the DD torque/TB model to change the values of this ratio at WOT. hopefully this clears up where you are trying to get to with the torque values.

[Plimmer]

Thank you for the input, I'm going to try both, but will be on the weekend, since that is the only time I get to fiddle.

[4wheelinls1]

What HPF said may help. I am guessing torque 1 and 2 refer to torque at which spark and ETC cut.

If you take your ETC TQ request and divided it by the engine brake torque you get the torque ratio. Notice that if the request is higher than the engine torque the ratio will be larger than 1 and if its less it will be less than 1. The Fuel cut torque ratio is only used when ETC is less than engine torque(ratio less than 1) as you don't want it to cut fuel and cause a lean condition when the engine is being requested to make more power. That's why it can only cut fuel below a 1 ratio. Coyote cook book says to raise this to 1 but does not explain why. Above 1 it uses spark and ETC to limit torque. Also notice the spark only torque ratio is used when ever the ratio is above 0. So it can cut spark any time the engine is not in DFCO basically. Anywhere between 0 and 1 it can use one of the three it sees fit or a combination.

I looked through your log and see at WOT your torque ratio is .85 to .99. If you don't want to risk a fuel cut at WOT I would suggest lowering your fuel cut torque ratio for DD to less than this not to low or you will get spark and ETC rather than fuel cuts. If you want it to stop pulling spark you need to raise the spark only torque ratio above .99. Or you can manipulate the DD torque/TB model to change the values of this ratio at WOT. hopefully this clears up where you are trying to get to with the torque values.

Good info. Thanks

[Plimmer]

Great news, changed the max torque 1 and 2 to 800 and I set the spark cut torque ratio to 1 and I'm not getting torque control as spark source anymore. I only did a few logs, but all seem good. I'm also impatient so made 2 changes at once, so don't know which change did it.

I also tried to change the GT350 throttle body values for predicted area at WOT back to the stock values, but this had no effect on ETC torque request. So I still don't know how ETC torque request is calculated and my logs still show ETC torque request much lower than Engine Brake Torque, but at least I don't seem to be getting any torque control intervention.

[murfie]

https://www.google.com/patents/US6705286

So one part of the TB model is to calculate the angular position of the throttle valve. Why? to make sure the position sensor is accurate. The other part is to calculate air flow through the throttle valve. Why? To get an engine load value(absolute load). So unless you change the effective area values you wont change the TQ value calculated from it. part of the GT350 model WOT relates 92* pedal to anywhere between 5.7"-6.68" effective area which The stock value 5.9" WOT falls between.

The MAF sensor can also be used to get an engine load value(air load).

The DD table uses throttle valve position vs RPM to get a desired TQ. Friction Tq gets added to this value to get indicated TQ. Indicated TQ is then calculated to a load value(calculated engine load).

If MAF load is less than TB load a ratio of one is used and no modification to DD torque is made. If MAF load is greater than TB load the Throttle closes til MAF load and TB load are equal. Spark can also be reduced to achieve a ratio of 1.

Load can be converted to TQ based on the engines VE.

ETC torque and engine toque are compared like the TB load and MAF load.

The two values are compared to DD torque. If ETC TQ exceeds DD fuel to cylinders can be cut as TB is assumed stuck open. If engine TQ exceeds DD this can be caused by a dirty sensor giving an inaccurate reading a fuel cut may be excessive and other methods can be used. The CLIP/ADD allows some wiggle room for the ECU to use methods of intervention that are more subtle to the driver for both MAF and TB.

[Plimmer]

Wow, thanks for that, I'm going to have to read it multiple times to make sure I understand it.

I did do a bunch of logs today to learn more:
Doubled the driver demand table and Engine Indicated Torque and ETC Torque Request increased but no noticeable change to Engine Brake Torque
Doubled the torque table and Engine Brake Torque went up but Engine Indicated Torque and ETC Torque Request were roughly the same. In fact during this one the throttle closed a little during a portion of the run to limit airflow, so the Engine Brake Torque to ETC Torque request ratio must have exceeded some limit.
All changes made to a base test map, so not cumulative changes. I think that is consistent with what you described above.

I also messed with the air charge multiplier and the offset in the Speed Density area, but didn't seem to do anything.

Also, now I understand why my changes to the TB tables did nothing, since my change was still in the WOT range.

I've also found that setting my DD for WOT at Engine Brake Torque + 25 seems to work reasonable well, and I've got CLIP/ADD and Oscillation both disabled. I"ll turn them back on at some point to see if all good. Turning CLIP/ADD was an easy way to eliminate the slight part throttle surging I was still getting.

[R8Bill]

What HPF said may help. I am guessing torque 1 and 2 refer to torque at which spark and ETC cut.

If you take your ETC TQ request and divided it by the engine brake torque you get the torque ratio. Notice that if the request is higher than the engine torque the ratio will be larger than 1 and if its less it will be less than 1. The Fuel cut torque ratio is only used when ETC is less than engine torque(ratio less than 1) as you don't want it to cut fuel and cause a lean condition when the engine is being requested to make more power. That's why it can only cut fuel below a 1 ratio. Coyote cook book says to raise this to 1 but does not explain why. Above 1 it uses spark and ETC to limit torque. Also notice the spark only torque ratio is used when ever the ratio is above 0. So it can cut spark any time the engine is not in DFCO basically. Anywhere between 0 and 1 it can use one of the three it sees fit or a combination.

I looked through your log and see at WOT your torque ratio is .85 to .99. If you don't want to risk a fuel cut at WOT I would suggest lowering your fuel cut torque ratio for DD to less than this not to low or you will get spark and ETC rather than fuel cuts. If you want it to stop pulling spark you need to raise the spark only torque ratio above .99. Or you can manipulate the DD torque/TB model to change the values of this ratio at WOT. hopefully this clears up where you are trying to get to with the torque values.

Can you make all values to zero and stop any reductions?

SOTR.jpgFCTR.jpg

[Plimmer]

Can you make all values to zero and stop any reductions?

SOTR.jpgFCTR.jpg

This ECM is so mysterious and secretive, you've just got to do what I finally decided to do, find a quiet road and flash, log, check, then repeat. Some afternoons I go till my laptop battery dies.

Also I'm slowly learning to make changes by doubling numbers or halving numbers to see the effect, if you make little changes its difficult to see the difference. Maybe I'm a cowboy, but that seems to be the only way to understand this HDFX logic.

[murfie]

Making it all zeros may prevent the fuel cuts, but not spark or throttle cuts. In fact setting it to zero for spark may make it worst. By allowing it to happen more often.

I read not to use a power inverter, but I do so that my battery doesn't die. I turn it off as well as other accessories while flashing the ecu that's all. Playing with the editor is one way to figure out what things do. The ecu is full of checks, balances, and limits so is still hard to figure things out. Knowing this makes me feel less like a cowboy and more like a child playing cowboy though.