2017 pulled timing

[cesar]

I was tuning this 17 silverado, bone stock just E85. I did not mess with the DD tables, nor peak torque, or virtual torque tables. I zeroe'd out most spark modifiers (at least anything that would pull timing) and when I would command say ~23* at WOT (.6+ g/ cyl) it would NOT come anywhere near close that timing value. It would command around 16*. I logged all timing modifiers and none of them were pulling timing. 0 KR, all that good stuff. Now I have been tuning for a while now, bunch of gen 3 and gen 4 controllers (I am saying this to get past the usual discussion of "you sure there wasn't anything else pulling timing?"). So what I had to do, and am quite embarrassed to admit, i had to command approximately 29 degrees in the main timing table to get in the low 20s of commanded timing. This is a temporary solution for now. My question is, despite the vehicle being completely stock, is there a possibility that timing was being pulled due to me leaving the DD tables factory?

I have a very general sense of what needs to be done. Log Avg Pedal Pos vs ETC Position and they have to match, if they don't, then something will be done so they do match. I.E. if pedal pos is higher than ETC, then I am being limited (spark maybe? or just the throttle not opening all the way). This is the second time this happens to me, and it seems to be in 2016+ trucks so far. Am I missing something? maybe I should have increased the DD values and see if the timing went up to commanded. But if thats the case, why would commanding more timing (29*) bring the timing to low 20s? Shouldn't it still be at 16* no matter what if the torque demand tables had anything to do with the timing being pulled?


Hope I get some answers, I have NO logs saved unfortunately. pedal position and etc matched at wot, 99.6%.

[TriPinTaZ]

Log Torque Management Advance. This value subtracts from total timing advance commanded. Also, are you sure you have properly adjusted all of the E85 multipliers (and subtractors)?
Did the truck come with an E85 sensor from factory or did you have to add one? Also, post your tune.

[cesar]

I will log that next time. But what would be the culprit? The DD table or the peak torque table? What I assume is happening is there's a pedal request, axle torque request checks fine, but engine torque is too much so the ecu pulls timing to match that torque requested? Would that be in the DD or the peak torque tables to address?

And I thought torque calculations was correlated to airflow, so how does the pcm calculate torque if the airflow is the same but the timing is changed? Does it have torque estimation based on other methods than airmass? Rate of change in rpm?

I would like to build on this thread and GEN V tuning.. not much info out there. Well correct info, on how these controllers work.

I don't want to buy the tuning school gen V book yet .

[TriPinTaZ]

Before you get ahead of yourself, first look and see if it is indeed Torque Management Advance kicking in at full throttle. And the book does not have anymore info than you will fine here. The info is here , but you have to spend the time and read through many threads.

There are a variety of reasons that TMA would kick in at WOT. The most common would be the transmission max torque values, that's where I would look first. Only E85 wouldn't be enough to exceed the peak torque table, or need any sort of VVE or DD table changes. Virtual Torque can affect TMA kicking in, but again, with only E85 you're not far enough off to cause any issues.

VVE and Virtual Torque tables are actually just tools to input values and calculate Torque Coefficients for both MAP and MAF based calculations.

Anyhow, without posting your tune I can't really see if anything sticks out. Don't worry, no one wants to steal a bone stock E85 tune. But posting your tune would help others help you.

[Ben C]

You may not be aware that hp tuners auto saves logs, have a look in the install folder, under vcm scanner then logs. I think that's the correct location

[cesar]

Thanks Ben. I'm aware.

And TriPintaZ, i know all about VVE, tuned countless e38s in SD before the tool existed, with BC's tool. I am not new to this, I am new to Gen V however so I am all ears. I am confused on the application of the virtual torque tool and what it is used for. And lol, I could care less if a "toon" file was stolen. I just didn't have the laptop with me at the time of making the thread, and omitted uploading the file. As you said, it is a bone stock e85 tune so not much to see. I have mentioned I zeroe'd most of the timing modifiers. You can also see how i sneaked in the extra timing via the EQ spark correction. The tune file is below. Once again, thanks for taking the time to respond and check this out.

[TriPinTaZ]

I see nothing in the tune that would not allow the timing you are asking for. Next I would datalog TMA to see if its kicking in.

[mjsmith2]

I believe I have run into the same issue today. 2015 Silverado 5.3. I started leaning out the PE values from .77 to .85 lambda and with no other changes lost 10* at peak torque. No crazy knock corrections and as mentioned above the torque management advance was not pulling timing either. Best I can tell the torque modeling system includes timing and fuel values in its calculations such that my change to the PE table caused it to pull enough timing to make the same power. I'm guessing the torque model needs to be modified as well but I have yet to figure out exactly how to go about that.

Capture1.jpg
Capture2.jpg

[veee8]

Check your humidity spark table......

[TriPinTaZ]

You all should be logging all Spark Modifiers. It looks more like Torque Management Advance to pull that much timing. Humidity Spark tables don't have a high enough value to pull that much timing. But until you log all of your spark modifiers to see exactly which one is pulling the timing, you're just guessing.

[mjsmith2]

Are you referring to a different torque management advance pid than the one I was logging? During both runs it stays at 0. I believe it is correct as it shows tons of timing being pulled on wot upshifts as expected.

[TriPinTaZ]

Are you referring to a different torque management advance pid than the one I was logging? During both runs it stays at 0. I believe it is correct as it shows tons of timing being pulled on wot upshifts as expected.

ah yes that is the right one. I didn't realize you were not the OP.

Are you high and low octane tables different? Is it possible the car is switching to the low octane table?? Post your tune and I'll take a look and see if anything obvious pops out.

[mjsmith2]

2015 Silverado 87 + Flex v8.hpt
2015 Silverado Stock.hpt

Capture3.jpg

The screenshot is from another run where I tried increasing the driver demand and peak torque tables by 10% but that made no change to the timing issue and made the drive-ability noticeably worse. What was interesting was that doing this increased the driver pedal torque request and peak torque values, but the pedal final, commanded axle, and engine torque values all stayed the same.

*edit* Yes the high and low tables are different. Based on the knock learn value I would assume its using the high octane table but I'll look into it.

*edit 2* Base timing matches the high octane table so that is out. The 4*+ missing is still odd to me.

[TriPinTaZ]

I don't really see anything in the spark tables that would explain the missing timing either. I thought maybe the Max torque Alcohol Adder or as mentioned above the humidity modifier but that is only a guess.

[1 Slow GTO]

2015 Silverado 87 + Flex v8.hpt
2015 Silverado Stock.hpt

Capture3.jpg

The screenshot is from another run where I tried increasing the driver demand and peak torque tables by 10% but that made no change to the timing issue and made the drive-ability noticeably worse. What was interesting was that doing this increased the driver pedal torque request and peak torque values, but the pedal final, commanded axle, and engine torque values all stayed the same.

*edit* Yes the high and low tables are different. Based on the knock learn value I would assume its using the high octane table but I'll look into it.

*edit 2* Base timing matches the high octane table so that is out. The 4*+ missing is still odd to me.

Ran into this last night (though not as much of a reduction) on a bolt-ons '15 5.3 Silverado. Gotta up the virtual torque tables. In addition to the loss in spark, look at your TPS % at WOT - it being that low means the PCM is shutting it to drop torque.

[cesar]

I have zeroed out the humidity tables and no change. This seems to be a 2016+ issue as that's the only time I see this. This always happens at peak torque too. In addition I have zeroed out the alcohol adder tables. 1 slow gto, what exactly do you up in the virtual torque tables? And why? There's various ignition values on the y axis, which exactly do I modify?

[sevinn]

I have zeroed out the humidity tables and no change. This seems to be a 2016+ issue as that's the only time I see this. This always happens at peak torque too. In addition I have zeroed out the alcohol adder tables. 1 slow gto, what exactly do you up in the virtual torque tables? And why? There's various ignition values on the y axis, which exactly do I modify?

Is the AC on by chance?

[cesar]

AC is off

[cesar]

bringing this back to the top, had this same BS ass issue AGAIN here are more logs, theres a difference of more than 7 degrees.

Anyone have any ideas wtf is going on? the 2014s do not have this issue.why is the timing so low.hplwhy timing very low, not commanded.hpl


THROTTLE DOES NOT CLOSE, TORQUE REQUESTS SEEM TO BE HIGHER THAN ACTUAL TORQUE GENERATED.

DESIRED THROTTLE MAP EXCEEDS ACTUAL MAP SO ITS NOT THE BLADE SHUTTING,

TORQUE MANAGEMENT ADVANCE IS 0 THROUGHOUT THE PULL

EXCUSE THE CAPS, MY KEYBOARD IS ACTING UP.

EDIT** THIS ISSUE DOES NOT HAPPEN IN 2014S AND 2015S. THE VIRTUAL TORQUE TABLES ARE IDENTICAL FOR 2014S AND THESE 2016S/2017 SILVERADOS.. SO SURELY IT CAN'T BE THE VTT. IS THERE A SPARK TABLE MISSING? I KEEP HAVING TO ADD IGNITION VIA THE PE TABLE. IT ALWAYS SEEMS TO BE AROUND 7 DEGREES DIFFERENCE.

I MODIFIED PEAK TQ TABLES, DD TABLES, NOTHING WORKS.

[sevinn]

bringing this back to the top, had this same BS ass issue AGAIN here are more logs, theres a difference of more than 7 degrees.

Anyone have any ideas wtf is going on? the 2014s do not have this issue.why is the timing so low.hplwhy timing very low, not commanded.hpl


THROTTLE DOES NOT CLOSE, TORQUE REQUESTS SEEM TO BE HIGHER THAN ACTUAL TORQUE GENERATED.

DESIRED THROTTLE MAP EXCEEDS ACTUAL MAP SO ITS NOT THE BLADE SHUTTING,

TORQUE MANAGEMENT ADVANCE IS 0 THROUGHOUT THE PULL

EXCUSE THE CAPS, MY KEYBOARD IS ACTING UP.

EDIT** THIS ISSUE DOES NOT HAPPEN IN 2014S AND 2015S. THE VIRTUAL TORQUE TABLES ARE IDENTICAL FOR 2014S AND THESE 2016S/2017 SILVERADOS.. SO SURELY IT CAN'T BE THE VTT. IS THERE A SPARK TABLE MISSING? I KEEP HAVING TO ADD IGNITION VIA THE PE TABLE. IT ALWAYS SEEMS TO BE AROUND 7 DEGREES DIFFERENCE.

I MODIFIED PEAK TQ TABLES, DD TABLES, NOTHING WORKS.

I looked through your logs and it does seem strange. It's doing it even before your pulls.