2014 c7 416 engine tq management at idle retarding timing to -10

working on a c7 a7 with a built 416 cid engine, big cam, ecs blower, meth. startup and drivability good but tq management is pulling timing at idle as much as -10 after running a few minutes, and starts to show a tad bit of knock. I am logging all tq values and I am thinking it is pulling timing to control tq at idle. any help would be great added tune and log file. I have made alot of changes to tq tables so dont ridicule too much as i am just at a loss at this time. 1st stroker engine tune on a gen5. I also have not tuned for WOT yet.


Attachment 68482
Attachment 68483

I'll look later if I get time... but I bet tq is too high causing it to pull timing... plus there are several things that need to be done to get these to idle right!

It looks like you are having a similar problem that I was having when I started my 2016 Camaro. Looking at the file you are commanding 900 RPM idle but in the log it seems to be trying to run at 800 RPM. I don't see the commanded idle RPM in your log, but the idle does seem to be lower than commanded. My research on here shows people doing many things to correct it. What I had luck with was cutting the external load (all oil temps up to 1200 RPM) by 50% this allowed a stable idle and better drivability. To fine tune it, I subtracted 20 (just a number value) from 100mG to 600mG and up to 1200 RPM in the Torque editor. Then extrapolated (seems to blend the numbers on its own). Then subtracted the same value from the MAP table in the torque editor (30kpa to 70kpa up to 1200RPM) and extrapolated and then clicked calculate coefficients. If yours is still pretty far off, try 40 as a value to subtract. I can now idle at 750 with 17-18 degrees timing. It seems different operating systems require a different way of adjusting, so please post up what ends up working for you.

Also, I kept all the Peak torque, overboost torque, idle reserve, and adaptive idle tables stock

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Originally Posted by Kyle_Customizer

It looks like you are having a similar problem that I was having when I started my 2016 Camaro. Looking at the file you are commanding 900 RPM idle but in the log it seems to be trying to run at 800 RPM. I don't see the commanded idle RPM in your log, but the idle does seem to be lower than commanded. My research on here shows people doing many things to correct it. What I had luck with was cutting the external load (all oil temps up to 1200 RPM) by 50% this allowed a stable idle and better drivability. To fine tune it, I subtracted 20 (just a number value) from 100mG to 600mG and up to 1200 RPM in the Torque editor. Then extrapolated (seems to blend the numbers on its own). Then subtracted the same value from the MAP table in the torque editor (30kpa to 70kpa up to 1200RPM) and extrapolated and then clicked calculate coefficients. If yours is still pretty far off, try 40 as a value to subtract. I can now idle at 750 with 17-18 degrees timing. It seems different operating systems require a different way of adjusting, so please post up what ends up working for you.

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Where is the tq editor table and Map table for tq editor? (not sure what table that is)

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Originally Posted by big 3 racing

Where is the tq editor table and Map table for tq editor? (not sure what table that is)

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In beta.. top left of screen under Edit right beside VVE, called virtual tq

Attachment 68486


here is with the idle tables back to stock other than rpm. i cut the load limit (external load limit) by 50% like you said. made little to no change but logged desired rpm and you are correct it is not matching

i guess i need to ask for beta then

The above changes might work ok for a small cam, won't cut it with a big cam...

OP, what size cam in the 416?

Yeah, beta helps a bunch. Just reduce the numbers in the torque editor. I have had no luck generating a graph to get a measured error and make a change that way. I just add -20 to the idle cells and surrounding ones and let it extrapolate from there. I'm sure it's a torque calc error. You can also multiply the idle RPM areas of the EQ ratio torque coefficients table by .75 and see if that helps. I did that on my first go around with my car. But playing with the torque editor made that change unecessary.
Also build the table in the editor to match what your car is capable of and get good resolution. My car hits 1.25 cylinder airmass so I made it read 0 to 1300 grams at 50 intervals iirc. And map 0 to 150kpa with 5 increments. Whatever it allows max resolution. And I just "linked" all the spark tables to make the same change. I didn't do each table separately.

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Originally Posted by Ben Charles

The above changes might work ok for a small cam, won't cut it with a big cam...

OP, what size cam in the 416?

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Yeah what size cam is in there? Mine is not crazy by any means.

whew sounds complicated. my 416 only required changes to one idle table and no torque tables. maybe I did it wrong.

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Originally Posted by Kyle_Customizer

Yeah what size cam is in there? Mine is not crazy by any means.

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Cam is 235/247 .657/660 114+4

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Originally Posted by Ryan_Abel28

Cam is 235/247 .657/660 114+4

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Literally just did a 229/242 in a 6.2 truck with s tory converter (needs converter) for a 416 that's not that big of a cam..
Many ways to skin a cat here.. still not on my tuning computer, but I'll take a look when I can

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Originally Posted by Higgs Boson

whew sounds complicated. my 416 only required changes to one idle table and no torque tables. maybe I did it wrong.

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Care to share what you did?

Attachment 68519

Interesting Higgs Boson. So you had success with increasing the External Load values around idle? I know for fact mine wanted to try and run at 500 RPM (commanding 750) when I increased those numbers, it only got worse. It was going to the lowest amount of timing allowed. It's just crazy how all of these seem to be so different. Has anyone come up with a good way of logging the errors the ECM is compensating for? All I have come up with is if the timing is less than I am commanding, lower torque. If it's higher, then increase torque.

Quote:

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Originally Posted by Kyle_Customizer

Interesting Higgs Boson. So you had success with increasing the External Load values around idle? I know for fact mine wanted to try and run at 500 RPM (commanding 750) when I increased those numbers, it only got worse. It was going to the lowest amount of timing allowed. It's just crazy how all of these seem to be so different. Has anyone come up with a good way of logging the errors the ECM is compensating for? All I have come up with is if the timing is less than I am commanding, lower torque. If it's higher, then increase torque.

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might have been a result of you changing other things in the tune.

there are/were no changes to the torque model of any kind for it to idle properly.

and it goes without saying a perfectly tuned MAF and VVE.

I tried changing the virtual tq tables like mentioned and didn't make much change at all, kept taking 10 away from the same cells and no change just started to run awful. Tried changing the idle tables like higgs mentioned and seemed to be a little better at 1st then it started correcting. here is the log and the current tune.

Attachment 68624

Attachment 68625

I also tried subtracting from the Virtual tq tables -30 from both and tried it with the idle tables that higgs mentioned and still the same thing, pulling up 20 24 degrees of timing at idle for tq managment then that pulls the idle down.