Help me understand intergral and proportional airflow tables

[Allen Vos]

Again, the majority of your corrections will be elsewhere in a 4th gen and the "elsewhere" needs to be dialed in before even thinking about making corrections to any of this. However the airflow "limits" need to be set to your new idle airflow operating range. Read up on the min airflow thread, especially after Smokeshow says the operating strategy of these ECU's.

This is how I've taught myself to think of the adaptives. Are they pid controllers. Absolutely, but they're still dialed in for that engines current TB, airflow and torque. With that in mind, I truly believe there's a little miss-labeling on the adaptive tables. Yes they are representing rpm error and airflow, but they are in fact correcting for "torque errors" or at least they seem to be to me. With that train of thought re-look at the tables. To increase rpm and thus increase torque, you open the throttle plate (right side of the tables). If you need to decrease rpm and thus decrease torque, you then close the throttle plate (left side of the table). They're exactly the same going forward to the newer gens too, which funny enough almost everybody out there adjust. Go figure right Anyone can correct me if I wrong about this, but all of my own testing and tuning has shown just that. You can sometimes REALLY smooth out a big cam manual cars drivability with just lowering and smoothing about 4 cells to the right in the proportional table. Just depends on what's going on. Now am I saying go and adjust yours like that - NO, I'm saying if you still have problems down the road then it doesn't hurt to smooth things up a touch.

Sorry, I should have mentioned that I was only trying to understand the integral and proportional idle tables and did not want to get my own tune involved here.

For the record on my other post apparently it was the VVE below the idle that was lean causing my little blip so I need to iron that out.

I have no intention at this point to even touch the integral and proportional idle tables.


I really want to understand the integral and proportional idle flow inside and out and also hoping this post will help others like myself just starting out.

So if I understand you correctly , the integral and proportional tables work just like the spark over and under speed tables where "0" is your target RPM except it is adding and removing air by opening and closing the throttle blade?


You might have mentioned this but if you did, I'm not following so I would like to ask this again.

I also see an over and under speed error multiplier under adaptive idle. Are these error tables for proportional and integral or are they for something else?

So the numbers on the proportional and integral tables represent torque? How does it convert those numbers to air flow(G/S)? Is there a math formula it uses for this that we can see?


I seen you had mentioned the airflow limits and I didn't want to talk about my tune on this thread but I should mention to you that I set the integral airflow limits to 1 Gram higher than my idle and the car flared up to 1400 rpm on startup and came down to target(800 rpm) very slowly so I put it back the way it was. I am not sure why it did that but one more thing to mess with lol

[Allen Vos]

My LS3 car with a big cam ended up with the '14 Camaro SS PID values (this was the suggestion of the previous professional tuner for the car). The surging idle and stalling experience was a journey for me, and is the whole reason that got me into buying HPTuners and learning to tune. I thought that learning the PID's was the answer. It was not. Simply applying the Camaro PIDs did not solve anything for me. What did solve my issues was sorting out the min final airflow table, base spark, and OEM over/under spark values. I have made some very minor tweaks to over/under spark (as in .1 to .5 or so), not technically stock.

I still have the Camaro PID values in there, I should have taken them out, but they were forgotten over time as I was working out other more important issues...I suppose it would be a good experiment to roll back to my stock values (SS Sedan) to see what happens. So I guess I suggest the Camaro ones as an alternative since they seem to be working for me, it is an option and a config that is known to work. However, I think your OEM 'vette PID values will work just fine for you.

Bottom line though, I would just focus on the fundamentals for idle. The airflow PIDs are just a distraction from the finish line.

OK, cool. I had tried the Camaro ones you suggested and also the 2010 CTSV but did not notice much difference.

It looks like my issue all along has just been my VVE table being out a bit below idle so its been a frustrating time to say the least.

I still very much want to understand every aspect of the GEN 4 including proportional and integral tables

[LS ROB]

There shouldn't be over/under shoot in a correctly tuned system. Tuning PID is complex and there is not one size fits all method. Proportional?integral?derivative controller - Wikipedia

I haven't tuned a e38 / e67 throttle PID as I've never needed to make adjustments to it. I must have got lucky. However, I have tuned numerous first order industrial control systems, so I know enough about it to comment. 2nd order and high dead time systems I leave for the legit control engineers.

I stand corrected. I was under the impression that you would have oscillations from a P adjustment, BUT you don't have to make such a large correction. I wasn't really thinking like that. I have VERY limited experience with industrial PID controllers for process control in a classroom setting. (no real-world exp. yet) Agree with you on this. You win this time Sir. Suppose i should pay more attention in class next time. lol

[04silverado6.0]

I understand where you're wanting to go with this and it's always good to know how things work, but the majority of your idle tuning will be on the airflow side. I can give you the basics of how things work and you can take it from there.

In the adaptives you have your main two like what you're talking about. Proportional is immediate or your main big throttle controls. Integral is small and primarily ignition linked controlled. Both of these add on the right side of the table and take away on the left. The other important players that I think you might be missing are the airflow and rpm settings for those, not to mention the speed setting controllers for them.

At the top you have min rpm ref - this is the min rpm for the adaptives. A lot of people mistakenly raise this to the idle rpm with cams because it's set around the idle rpm with the factory settings, but as we know cams like to lope and the last thing you want is it jumping in and out of idle adaptives. This should be left down around 500 rpms.

At the bottom you have airflow limits - cams add airflow - pay attention to the g/s or lb/hr settings in this table and how that may have changed in comparison to how it was setup from the OE operations. Airflow Max under throttle follower needs to be observed for the same reason. Only set them a gram or two above observed idle airflow.

Decrement steps - higher numbers close the throttle quicker. Lower numbers slower. Typically only ever had to touch this on big cammed motors and even then it was rare. You can smooth up throttle plunges with clutch in's using this alone while keeping the airflow tables nearly stock.

There's a couple of other important players on top of this that people often don't even consider.

Effective area - min, max settings. Min combined with percent max will be your throttle stops. Big cam = more air = throttle needs to be held open more. This will be achieved not only here, but in your min air table. If you're increasing your min air ANY at idle above the 1000 or 1200 rpm columns then these settings need to be raised. Use the scanner and set these so at a hot idle you can still force it to idle at least 150 to 200 rpms below commanded. This way you still have a safety net designed into it for vacuum leaks or whatever. The min settings should never need to go above 80 from everything I've ever seen. Min brake is how much the throttle will close for engine braking.

Throttle follower. Not entirely sure, but I've always set it just under delivered torque. Again, this way the throttle has the capability of closing if needed. I like to think of this table like how the pedal progression combined with the DD tables are used in the newer stuff, so set under delivered and mostly negative everywhere. The torque model on it's own will help A LOT with throttle and idle control. 4th gens respond well to plugging delivered right back into the models even though it's not correct.

Then since it's all airflow controlled and airflow = fuel, fueling needs to be dialed in at full operating temp before touching anything including the very basics such as inj timing and O2 settings.

It seems to me the throttle follower-torque table is the representation for airflow. I believe the lower/more negative is using less throttle follower assistance, not necessarily less airflow. i would say it is used to calculate airflow from the torque model and we can think of this as a "Modifier" table instead of something like the actual airflow table in gen 3.

[04silverado6.0]

Throttle follower-torque definitely becomes less aggressive with lower/more negative numbers. One quick change on this truck seems to have helped the "stuck throttle" feeling.

[GHuggins]

Throttle follower-torque definitely becomes less aggressive with lower/more negative numbers. One quick change on this truck seems to have helped the "stuck throttle" feeling.

When you say "stuck" you mean delay to response? Making it negative like that all through idle helped with that? Is your VE table tuned? Datalog of idle torque by chance?

[hjtrbo]

But at idle...the base desired airflow is determined by the torque model. Corrections are done independently by air and spark, but that initial airflow target is all APC torque.

It seems to me the throttle follower-torque table is the representation for airflow. I believe the lower/more negative is using less throttle follower assistance, not necessarily less airflow. i would say it is used to calculate airflow from the torque model and we can think of this as a "Modifier" table instead of something like the actual airflow table in gen 3.

Good, good, very good.

Once again we circle back to the torque model around and just off idle. Take this recently applicable scenario with our new member AVoss. Running with Smokeshows statement, we make the conclusion that a torque model, if out, would dump in a bunch of air following a throttle blip. That air is then blamed to be the integral airflow. So integral adjustments are made. That then upsets 0% APP idle. A viscous cycle now ensues with no real result...

So.... Do we make a mild massage to the torque model to get the desired air inline with actual air, then finesse the thrtl follower table to suit our personalities?

[Allen Vos]

Good, good, very good.

Once again we circle back to the torque model around and just off idle. Take this recently applicable scenario with our new member AVoss. Running with Smokeshows statement, we make the conclusion that a torque model, if out, would dump in a bunch of air following a throttle blip. That air is then blamed to be the integral airflow. So integral adjustments are made. That then upsets 0% APP idle. A viscous cycle now ensues with no real result...

So.... Do we make a mild massage to the torque model to get the desired air inline with actual air, then finesse the thrtl follower table to suit our personalities?

I will need to start learning and following the torque model thing and learn it as my crummy throttle blip is still there lol.

After I get the VVE dialed in a bit better, ill post logs again and start working the torque model

[Allen Vos]

When you say "stuck" you mean delay to response? Making it negative like that all through idle helped with that? Is your VE table tuned? Datalog of idle torque by chance?

What should Idle torque be with a modified camshaft?

granted my tune needs some attention still, but its very low to the tune of 5-15 NM at idle.

Does that seem right?

[hjtrbo]

I've always figured 30 up to 50Nm depending on accessories running. I'd like to hear what others are looking for...

[smokeshow]

What should Idle torque be with a modified camshaft?

That's the question of the century, isn't it?

[Allen Vos]

That's the question of the century, isn't it?

ha ha yes man. is a low torque like mine 5-15 anything to worry about?

[hjtrbo]

Here is the pumping loss data for a L76. Ignore the axis headings, just threw this together.

[hjtrbo]

And this is the acc drive friction table in Nm

[ns158sl]

Are the rows "Torque Factor"? Im still wrapping by head around that "term" and how to comprehend it. Is the data in Nm as well?

[hjtrbo]

I just grabbed a spark table to dump these numbers into as it was big enough.

x the row numbers by 100 to give kPa. I haven't looked at these for a while. My assumption of 30-50 is close. Better 30-45Nm

[hjtrbo]

Whether that range I said is right or not? I know stock cam that's about right from logging stock cars. But cam overlap and all changes pumping losses. Not something I've come across research paper data on just yet. That said, 30 has been working for me.

[ns158sl]

AH ok it is based off KPA! thank you. Anyway you can use your handy work on an LS7 file?

[hjtrbo]

no no no lol.

RE is not a hobby. It's become an addictive cancer on my free time that preys on my weakness of never leaving a puzzle unfinished.

[ns158sl]

RE is not a hobby. It's become an addictive cancer on my free time that preys on my weakness of never leaving a puzzle unfinished.

Lmao!!