Torque management advance pulling timing

[vettemakesemwet]

2015 Chevrolet Silverado 6.2, 8 speed auto 4wd. Maggie TVS1900 supercharger and corsa cat back exhaust. On acceleration sometimes TMA pulls timing, sometimes the throttle closes some too. Predicted engine torque source says trans when this happens, but not shifting gears during this time. Pulling my hair out trying to figure out what is causing this. Can someone take a look and point me in the right direction? Look around the 3:32 time mark for it, can see it other times in the log as well.TMAdip.hptlog1.hpl


Thanks in advance!(pun intended)

[vettemakesemwet]

sub question, can the tcc be applying and causing timing and/or throttle to be pulled?

[FastV]

2015 Chevrolet Silverado 6.2, 8 speed auto 4wd. Maggie TVS1900 supercharger and corsa cat back exhaust. On acceleration sometimes TMA pulls timing, sometimes the throttle closes some too. Predicted engine torque source says trans when this happens, but not shifting gears during this time. Pulling my hair out trying to figure out what is causing this. Can someone take a look and point me in the right direction? Look around the 3:32 time mark for it, can see it other times in the log as well.TMAdip.hptlog1.hpl


Thanks in advance!(pun intended)

I'm am in no way an expert in this, but when I looked at the Scan I saw that your Driver demand Tq was lower than Actual Delivered Tq, that's probably why your throttle is closing. When I had this issue I had to adjust my VTT to get if from closing the throttle. That's just what worked for me thought, not saying that's the cure or cause. I'm sure there are way smarter people in here with more experience that can answer this question for you..

Good luck
Ryan

[TriPinTaZ]

Driver Demand Torque requested is from your DD tables. If it is lower than delivered then your torque model is off. I'm assuming you've made changes to your MAF and or VVE table?

[vettemakesemwet]

MAF and VVE are dialed in pretty close. Bumped the VTT up to a little above what it should be making. Trying to get rid of the timing management advance, and the sometimes closing throttle so I can dial those in the rest of the way. Didn't touch the DD tables, and maybe this is where I went wrong. Just so I am understanding correctly from the PIDs in the log, am I looking at the driver pedal, or driver final axle torque request to compare it to actual axle torque delivered?

[vettemakesemwet]

Been poking around, think I may have a solution, maybe. Watching the log again I can see where the actual is off from the requested. Provided I am looking at the right stuff. I need to bring up the driver demand in those areas to exceed what the actual torque would be at that throttle opening, so it stays open. Since this is all torque management, would this trigger the torque management advance as well as closing the throttle body in relation to the DD table vs the requested/actual torque numbers?

[FastV]

Been poking around, think I may have a solution, maybe. Watching the log again I can see where the actual is off from the requested. Provided I am looking at the right stuff. I need to bring up the driver demand in those areas to exceed what the actual torque would be at that throttle opening, so it stays open. Since this is all torque management, would this trigger the torque management advance as well as closing the throttle body in relation to the DD table vs the requested/actual torque numbers?

Correct! add to the driver demand tables will bring up the amount of Tq requested. This will reflect in the DD Tq req pid the purple one. The Purple one should always be higher than than the others blue and lime green. Good luck.

Regards,
Ryan

[vettemakesemwet]

I'm not seeing purple or blue. Made some changes and still no purple or blue. Mine starts green and goes from that to yellow to orange. Bumped it up in the areas where I was making more than "requested". Will try it out and see how it works. Thanks for the help guys!

[FastV]

I'm not seeing purple or blue. Made some changes and still no purple or blue. Mine starts green and goes from that to yellow to orange. Bumped it up in the areas where I was making more than "requested". Will try it out and see how it works. Thanks for the help guys!

Your may have different colors. The pid that is labled DD Tq Req should be higher than the other 2 at all times.

[TriPinTaZ]

MAF and VVE are dialed in pretty close. Bumped the VTT up to a little above what it should be making. Trying to get rid of the timing management advance, and the sometimes closing throttle so I can dial those in the rest of the way. Didn't touch the DD tables, and maybe this is where I went wrong. Just so I am understanding correctly from the PIDs in the log, am I looking at the driver pedal, or driver final axle torque request to compare it to actual axle torque delivered?

Yes start by increasing your Driver Demand at WOT. If you have changed the MAF and VVE then the car is calculating a different torque value due to the airflow changes. If you increase airflow you need to increase Driver Demand, and at some point you may need to REDUCE Virtual Torque. It just depends. What you really want is for reported Engine Torque to match what the car did when it was stock, even if the car is making more power than that. This way it keeps most things in line and you just need to tweak here and there. I've seen it done numerous ways but its all about keeping the torque model happy. Automatic cars are more difficult because you have to worry about reported torque to the TCM so they will shift properly, where in Manual cars you don't.

[vettemakesemwet]

Never saw it stock. It had a PE raped tune in it, and nothing was done with anything torque related. I've had to tune it from scratch. Coming from gen 3 stuff to this torque management system has been an eye opener and a major learning experience. Thanks for the advice!

[FastV]

Yes start by increasing your Driver Demand at WOT. If you have changed the MAF and VVE then the car is calculating a different torque value due to the airflow changes. If you increase airflow you need to increase Driver Demand, and at some point you may need to REDUCE Virtual Torque. It just depends. What you really want is for reported Engine Torque to match what the car did when it was stock, even if the car is making more power than that. This way it keeps most things in line and you just need to tweak here and there. I've seen it done numerous ways but its all about keeping the torque model happy. Automatic cars are more difficult because you have to worry about reported torque to the TCM so they will shift properly, where in Manual cars you don't.

What he said

[vettemakesemwet]

Yes start by increasing your Driver Demand at WOT. If you have changed the MAF and VVE then the car is calculating a different torque value due to the airflow changes. If you increase airflow you need to increase Driver Demand, and at some point you may need to REDUCE Virtual Torque. It just depends. What you really want is for reported Engine Torque to match what the car did when it was stock, even if the car is making more power than that. This way it keeps most things in line and you just need to tweak here and there. I've seen it done numerous ways but its all about keeping the torque model happy. Automatic cars are more difficult because you have to worry about reported torque to the TCM so they will shift properly, where in Manual cars you don't.

What he said

That helps me understand the rel;ationship with the torque management a whole lot better. Thanks again to both of you for the help. I will post an update later when I can get back to the truck.

[vettemakesemwet]

For the driver demand, you said to raise it for WOT, did that, but I have some 50-75% throttle issues with the TB closing too. I'm guessing bump those up a bit too, right? Not too crazy, and from what I've found in some more reading on the DD table, do not touch any of the negative numbers. Basically I should have it set at requested some amount above actual Am I on the right track with that? Tried setting up a histogram to help me find percentages/errors, but think I messed it up, any pointers on that?

DD edit helped loads for the throttle closing issue up at WOT, but it did not stop the timing pull after a shift. I understand pulling timing for a shift, but after timing comes back up it pulls some again then comes back. Happens in the log I put up in first post. Sometimes it says trans, sometimes FTEA. Then I remembered the other thread where FastV mentioned the base spark when I asked about the pulling timing there. Set the base up a bit in WOT areas to start, tweaked it after a few logs, and it is now pulling hard except 1-2 shift as it loses traction....lol. Thanks a million for the help guys. Y'all got me on the right track!

[FastV]

For the driver demand, you said to raise it for WOT, did that, but I have some 50-75% throttle issues with the TB closing too. I'm guessing bump those up a bit too, right? Not too crazy, and from what I've found in some more reading on the DD table, do not touch any of the negative numbers. Basically I should have it set at requested some amount above actual Am I on the right track with that? Tried setting up a histogram to help me find percentages/errors, but think I messed it up, any pointers on that?

DD edit helped loads for the throttle closing issue up at WOT, but it did not stop the timing pull after a shift. I understand pulling timing for a shift, but after timing comes back up it pulls some again then comes back. Happens in the log I put up in first post. Sometimes it says trans, sometimes FTEA. Then I remembered the other thread where FastV mentioned the base spark when I asked about the pulling timing there. Set the base up a bit in WOT areas to start, tweaked it after a few logs, and it is now pulling hard except 1-2 shift as it loses traction....lol. Thanks a million for the help guys. Y'all got me on the right track!

You are on the right track...add a bit to the DD table from 32-74% and form 0-80mph that will help with that area if you haven't done it yet. You are correct don't touch the negative numbers those are there for closed throttle. Glad to help....

Best of luck
Ryan

[TriPinTaZ]

In an automatic transmission when the TCM isn't tuned, raising the DD tables isn't going to solve the issue if it is the TCM reducing timing due to seeing too much torque. You likely need to reduce your VT tables at mid and WOT.

[FastV]

For the driver demand, you said to raise it for WOT, did that, but I have some 50-75% throttle issues with the TB closing too. I'm guessing bump those up a bit too, right? Not too crazy, and from what I've found in some more reading on the DD table, do not touch any of the negative numbers. Basically I should have it set at requested some amount above actual Am I on the right track with that? Tried setting up a histogram to help me find percentages/errors, but think I messed it up, any pointers on that?

DD edit helped loads for the throttle closing issue up at WOT, but it did not stop the timing pull after a shift. I understand pulling timing for a shift, but after timing comes back up it pulls some again then comes back. Happens in the log I put up in first post. Sometimes it says trans, sometimes FTEA. Then I remembered the other thread where FastV mentioned the base spark when I asked about the pulling timing there. Set the base up a bit in WOT areas to start, tweaked it after a few logs, and it is now pulling hard except 1-2 shift as it loses traction....lol. Thanks a million for the help guys. Y'all got me on the right track!

Trans S = Transmission Short term tq mgt (things like shifting, generally using spark only)
Trans L = Transmission Long term tq mgt (other stuff like protections, spark and throttle)
FTEA = Fast Torque Exit is the end phase of any torque management, there are various options for immediate exit, ramp etc

This posted by Chris from Hp tuners on another thread. Hope this helps.

Ryan

[vettemakesemwet]

In an automatic transmission when the TCM isn't tuned, raising the DD tables isn't going to solve the issue if it is the TCM reducing timing due to seeing too much torque. You likely need to reduce your VT tables at mid and WOT.

I found the peak torque was obscenely high, so I brought it down to realistic numbers. The timing pull is gone with the min spark table adjustment. Trans is doing well now, made a few adjustments and will try those out in a bit. Its the axle tq on some tables, and then engine torque on others that threw me for a loop. Started a graph with actual vs demanded and been tweaking that way as needed. Truck is running pretty good. I'll keep that in mind about the VT tables, and adjust as needed. Thanks again!

[vettemakesemwet]

Trans S = Transmission Short term tq mgt (things like shifting, generally using spark only)
Trans L = Transmission Long term tq mgt (other stuff like protections, spark and throttle)
FTEA = Fast Torque Exit is the end phase of any torque management, there are various options for immediate exit, ramp etc

This posted by Chris from Hp tuners on another thread. Hope this helps.

Ryan

Yeah, I had found that awhile back. What confused me was the FTEA right after a shift while still accelerating. Some hinky stuff for sure! Thanks for the info!

[vettemakesemwet]

Just wanted to give you guys an update. Once I got the throttle closing and TMA timing pull figured out, I did some more work on the VVE, got the MAF curve smoothed out alot better, and played with the torque model some. Was alot easier to dial in without being limited.

Through some magical fart in the wind changes made, the truck now pulls too hard in my opinion. First half of the pedal is fairly civil with some go to it. Second half of the pedal is holy shit we're going way too fast. It could be better and act a little more civilized, but this is a great starting point for further refinements.

Just want to thank both of you guys again for the help!