Just curious, why does this calculate out to a difference?
Shouldn't it be the same?
Just curious, why does this calculate out to a difference?
Shouldn't it be the same?
dynamic airflow comes from here:
And the maf calibration table is here:
It would seem that for you these 2 tables don't totally jive with each other. You need to set MAF frequency fail high hz to 0 under engine diagnostics / airflow tab. Then you can tune the VE table which is where your dynamic airflow value comes from. Then you can put the MAF setting back and under engine / airflow / dynamic tab under the column for dynamic airflow you set the high rpm disable to a low number like 200. This forces the ecm to use just the MAF sensor and you can tune that table.
These tables will dial in a lot easier if you first disable the variables like power enrichment, DFCO, and Cat over temp protection. These are not constants, they come in at different times and levels and they are not hard linked to any axis of the tables we are trying to tune and yet they can have adverse affects on the data we are trying to log. We should calibrate these tables without these things best we can. Only enabling them for the wide open throttle tuning.
Wrong yet again.Originally Posted by AutoWiz
dynamic airflow comes from here:
And the maf calibration table is here:
It would seem that for you these 2 tables don't totally jive with each other. You need to set MAF frequency fail high hz to 0 under engine diagnostics / airflow tab. Then you can tune the VE table which is where your dynamic airflow value comes from. Then you can put the MAF setting back and under engine / airflow / dynamic tab under the column for dynamic airflow you set the high rpm disable to a low number like 200. This forces the ecm to use just the MAF sensor and you can tune that table.
Dynamic airflow is a weighted, blended airflow model using both of the tables numbnuts posted. Those values are filtered and weighted/blended to give the number you see in Dynamic airflow. Unless you fail the MAF. Then it reverts to SD only.
Last edited by Eaglegoat; 05-24-2017 at 04:10 AM. Reason: HP tuners edit mobile edit button sucks
I'm asking if these numbers should match or not.
Seems like one guy is telling me to tune (or calibrate) my maf, then VE table.
I've done all that but used ve error, or whatever. Again, I'm just asking if these should match.
Or is it something like static compression ratio vs dynamic where it will be different?
If you've done things right they should be very close. Because of some of the filtering they won't always match in throttle transitions/transient fueling. But steady state cruising all your mass flow outputs should nearly match, Volumetric Efficiency airflow, Mass airflow and Dynamic airflow. You can match the units they display in on the charts so they are easier to compare.
Last edited by Eaglegoat; 05-24-2017 at 09:11 AM.
They'll never match. Even in pure MAF, dynamic is still a filtered and smoothed version of MAF airflow.
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So you are saying that tuning the ve table does not impact the dynamic airflow and that tuning the MAF table does not impact the maf airflow?
It sounds like you need me to post up more proof of my knowledge. Is that what nees to happen here? Do we all need to see some winpep8 driven eddy current goodness on youtube videos?
No. I'm saying the VE table is not the dynamic airflow table it's the VE table. I'm saying that tuning the MAF and the VE both can impact the dynamic airflow.
Also no one gives a crap about your YouTube videos. Go thump your chest elsewhere.
So then I was right and tuning the ve table and maf table will correct the correlation issue he was having. Right? So you were just destroying any good that might have come out of this thread for the sake of being an ass? Eaglegoat, You are my new best friend
Last edited by AutoWiz; 05-24-2017 at 06:16 PM.
Dynamic Airflow is the what I call the PCM's "FINAL ANSWER" when operating in the MAF/Blended mode and has been developed by using the filter characteristics like the ones found in the Prediction Coefficient tables. It is developed to increase the accuracy of the Cylinder Airmass calculation (G/cyl) during transient scenario's as MAF airflow is a key element in the calculation. additionally, the VE/VVE table is used to "test" the MAF airflow values and make sure they are in-line. If the gap between the two exceeds a certain criteria, then the PCM will revert to Speed Density. MAF and Dynamic Airflow will be close during steady state situations, but diverge greatly during hard acceleration/deep deceleration. Log them together and watch how they react.
In Gen IV/V we have Prediction Coefficients which are the fodder for the filter algorithm. Again, I do not know the exact workings of this algorithm other than it magically filter out transient over/under conditions impacting the Cylinder Airmass. We do not have these tables in a Gen III setup.
No matter whether you push the High RPM to 400 (what we call MAF ONLY), there is still some background filtering going on so you are never pure MAF....but close enough. Also watch the Dynamic Airflow parameter, Even with the High RPM Disable set to 400 rpm, and if your VE/VVE isn’t tuned well, you will see a change at the magical 4000 rpm mark….further supporting that there is some background filtering going on even in “MAF ONLY”. That is why I agree with Howard where you need to tune the VE/VVE at least to the 4000 rpm area and above can be roughed in.
If you are tuning in speed density, where you either have removed the MAF or have purposely failed the MAF, then the Dynamic Airflow equals the VE/VVE values of which I assume is VE/VVE only as I do not know of any background filtering taking place here. If so maybe someone else can chime in.
Just a few thoughts on the subject..
Ed M
Last edited by mowton; 05-24-2017 at 07:26 PM. Reason: corrected double statement on magical 4000 rpm.....
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The above post proves in my opinion that its probably best to start and at least roughly tune the VE/VVE tables before switching to Maf only. obviously the variables will impact you less if your VE table is atleast partially tuned, I have first hand experience with the above statements about the magical 4000 rpm spot. also first hand experience with noticing more stability in Maf only with my personal gen 4 tahoe tuning the VVE and setting it back to Maf only. we can always count on Ed.
This has gotten derailed now because of your guys' witch hunt against anything I have to say. Look at the first post. When those two tables get too far out from each other we get the dreaded p0106 code for map/maf correlation. These are the tables to tune how far out we can let those two tables get from each other..
And the process I gave to correct that correlation is damn near a direct quote from the tuning the right way books and placards. I just kept my explanation simple so as not to inundate and confuse this individual as I was already giving him a process to correct it. Or am I the only one here who has seen the tuning the right way course? That can't be.
The only thing Eaglegoat is clarifying is the VE table is not the Dynamic airflow table as you stated above. It is a value that is calculated by the PCM using the MAF, VE and Prediction Coefficients depending on which Airflow Model the PCM is using.This has gotten derailed now because of your guys' witch hunt against anything I have to say. Look at the first post. When those two tables get too far out from each other we get the dreaded p0106 code for map/maf correlation. These are the tables to tune how far out we can let those two tables get from each other..
And the process I gave to correct that correlation is damn near a direct quote from the tuning the right way books and placards. I just kept my explanation simple so as not to inundate and confuse this individual as I was already giving him a process to correct it. Or am I the only one here who has seen the tuning the right way course? That can't be.
Ed M
2004 Vette Coupe, LS2, MN6, Vararam, ARH/CATs, Ti's, 4:10, Trickflow 215, 30# SVO, Vette Doctors Cam, Fast 90/90, DD McLeod, DTE Brace, Hurst shifter, Bilsteins etc. 480/430
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[email protected]
Don't waste your breath Ed. He doesn't listen, he knows it all, he's awesome, he has YouTube videos. Thanks.
Hey buddy. How ya been? Have you been watching this thread that you destroyed? Did you see the part where it came out that the process you said was wrong was not just right but it came from the tuning the right way placards? Well ok. Just making sure. I kept my response relevant to help this person. It is your anger that wrecked this thread. Your seeing red at anything I type. Stop it buddy. Just calm down.
Reading comprehension isn't your strong suit is it? I never said the process you described was wrong, I said the VE table isn't the Dynamic airflow table. I literally could not care less about what your tuning school placards say. You might be able to do what your placards tell you, but you don't know a damn thing about tuning.
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