2012 GT throttle "overshoot" on tip-in phenomenon, Edelbrock supercharger

I'm having an irritating throttle "overshoot" during tip-in phenomenon that I can't seem to iron out. You can see the log (white trace is throttle body angle and red trace is throttle pedal position).

Attachment 105075

It causes a "lurching" back and forth during quick throttle applications. You can see it in the log:

Attachment 105074

Here is what the car has:

2012 GT
Manual trans
Edelbrock supercharger, "Stage 1"
Stock throttle body
Stock MAF
Long tube headers
no cats

The "easy" answer may be there's an issue with the torque model, but torque model changes don't seem to have an effect. I don't have the means to create my own torque model, so I've resorted to plugging in torque models (Edelbrock, Cobra Jet, Roush). Changing torque models doesn't seem to affect it (no better or worse with each).

A few targeted questions:

1) Is there something else I'm missing? Is there a way to "damp" the throttle body angle changes, perhaps?

2) Look at the Wheel Torque Error histogram. There are some pretty massive wheel torque errors. Is this normal?

3) Without a dyno at my disposal, is there a way to do some driving and logging to straighten this out?

I've attached my current tune file as well as the log file.

Any help you can provide is greatly appreciated.

--Wes

Attachment 105073
Attachment 105076

Nobody has any insight? Surely someone else has tackled this issue...

Under Speed Density, try setting Max Aircharge Load back to 1.00 and set MAP Max Delta above Baro Pressure to the maximum amount of boost pressure that you're planning and see if that makes a difference.

Quote:

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Originally Posted by Witt

Under Speed Density, try setting Max Aircharge Load back to 1.00 and set MAP Max Delta above Baro Pressure to the maximum amount of boost pressure that you're planning and see if that makes a difference.

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Noted with thanks. I'll give that a shot and report back!

In the mean time, I'm curious how changing what you suggested would affect throttle "overshoot" problem I'm experiencing. (Understanding the rationale will help me diagnose other issues in the future.)

Quote:

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Originally Posted by WesDuenkel

Noted with thanks. I'll give that a shot and report back!

In the mean time, I'm curious how changing what you suggested would affect throttle "overshoot" problem I'm experiencing. (Understanding the rationale will help me diagnose other issues in the future.)

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It may not be overshooting but actually clipping desired airflow after what you call an overshoot and pulling the throttle back. Desired throttle and actual throttle match initially and then desired gets clipped by something. Every time I've seen either max map above baro or calc max map too low, it gives drivability issues. I think almost doubling the max aircharge load may be masking a portion of it.

If after the changes, it still overshoots but doesn't pull the throttle back as swiftly or gives less IPC Tq Errors, I would then dial back driver demand engine torque.

Quote:

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Originally Posted by Witt

It may not be overshooting but actually clipping desired airflow after what you call an overshoot and pulling the throttle back. Desired throttle and actual throttle match initially and then desired gets clipped by something. Every time I've seen either max map above baro or calc max map too low, it gives drivability issues. I think almost doubling the max aircharge load may be masking a portion of it.

If after the changes, it still overshoots but doesn't pull the throttle back as swiftly or gives less IPC Tq Errors, I would then dial back driver demand engine torque.

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Noted with thanks. I'll try that and re-log.

Quote:

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Originally Posted by Witt

If after the changes, it still overshoots but doesn't pull the throttle back as swiftly or gives less IPC Tq Errors, I would then dial back driver demand engine torque.

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Sadly, no real improvement. If anything, it seems to pull back harder. The first trace, it throttle ramps up, but then snaps closed:
Attachment 105140

In this log, you can see the throttle basically closes completely before picking back up:
Attachment 105142

This is nutty. Any other ideas?

Here are the logs files:
Attachment 105143
Attachment 105144

I scaled back my driver demand, but that didn't help. This has a stock throttle body, but I wonder if something is off with the throttle body model. (I tried a stock throttle body model, but that didn't help either). Here's my latest tune:
Attachment 105145

do the 2012 have a switch under the electronic throttle section called "anti-shuffle" if so turn that off and see what happens.

Quote:

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Originally Posted by aaronson

do the 2012 have a switch under the electronic throttle section called "anti-shuffle" if so turn that off and see what happens.

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No, but there is "Tip In Managment" under "Pedal."

Engaging or disengaging it doesn't help. I've tried it.

Same with Engine > Torque Management > General > Oscillation Switch. No change in the behavior.

Update: I changed 44373 "Pedal Pos to WOT Start", and that made a massive improvement...BUT, immediately ran into another problem. First set it to 50 and car quickly went into limp mode, got code "P061B Torque Calculation Performance." Tried setting it to 100, and it (predictably) took longer to trip the code, but did eventually. Set it to 200, and it never tripped a code, but the effect was not as good, as the "pedal following" strategy was further into the throttle.

My wheel torque error max is set to 75,000. I've been advised not to set it higher.

Is there a way to avoid code P061B while maintaining a lower "Pedal Pos to WOT Start" value than 200? Admittedly, this is a bandaid...but I'm running out of ideas.

is your tip in retard zerod out?

also in your log when you tip in does the car lean spike? whats your optimum power pedal set to in the power enrichment and the VCT settings. If its a stock throttle body change everything in the throttle section back to stock. except turn off the tip in management and keep the wot start around 200-250.

Quote:

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Originally Posted by aaronson

is your tip in retard zerod out?

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Yes, though I've tried it stock and zeroed out, and it doesn't seem to make any difference.

make sure torque modulation and tip in modulation / oscillation is enabled

Quote:

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Originally Posted by aaronson

also in your log when you tip in does the car lean spike?

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A log is attached to the original post, but to answer your question directly: No, there isn't a lean spike. Lambda is steady.

Quote:

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Originally Posted by aaronson

whats your optimum power pedal set to in the power enrichment

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80. Stock is 90

Quote:

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Originally Posted by aaronson

and the VCT settings.

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79. Stock is 89.

Quote:

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Originally Posted by aaronson

If its a stock throttle body change everything in the throttle section back to stock. except turn off the tip in management and keep the wot start around 200-250.

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For some reason, the Edelbrock tune made changes to the Effective Area table, but I've tried substituting stock values, with no improvement to the behavior.

Quote:

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Originally Posted by decipha

make sure torque modulation and tip in modulation / oscillation is enabled

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I've tried turning those on and off, and it didn't have any real effect either.

I suspect there is something wrong with the throttle body model, or when I squeeze the throttle, the supercharger bypass closes off, throwing things out of whack.

Look at this log. There are MASSIVE wheel torque errors. Look at the ETC Throttle Angle Error. There are double-digit throttle angle errors. Something is off...

Attachment 105294

Quote:

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Originally Posted by WesDuenkel

I've tried turning those on and off, and it didn't have any real effect either.

I suspect there is something wrong with the throttle body model, or when I squeeze the throttle, the supercharger bypass closes off, throwing things out of whack.

Look at this log. There are MASSIVE wheel torque errors. Look at the ETC Throttle Angle Error. There are double-digit throttle angle errors. Something is off...

Attachment 105294

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Attachment 105295

Try this and report back.

Quote:

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Originally Posted by Witt

Attachment 105295Try this and report back.

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Many thanks. I see what you've done there. I'll give it a shot.

Quote:

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Originally Posted by Witt

Attachment 105295

Try this and report back.

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Had a chance to try out that tune file, it's DIFFERENT. The initial overshoot is less, but as you can see, now the throttle oscillates over a longer period.
Attachment 105440

Here's the log file:
Attachment 105441

Any ideas on what to try next?

Attachment 105454

Try this, Your tune does need quite a bit of dialing in still. I changed your drivers demand and a lot of map settings, torque limits, map limits, and rescaled your tables to ressemble your load as well. Let me know how it acts.