gday all just trying just trying to set up my pids list and when it comes to the calculated maf pid all i seam to have is a calculated maf,not corrected.yet it is not supported by my pcm.im running os 01290005 osid v5.how will this affect doing calc.maft.
thanks
Looking for some insight into the calc_pids.txt. I've been away from this for an extended amount of time and I'm trying to brush off the cobwebs. A lot has changed, including the version of EFILive from V7.5 to V8.
A couple generic questions.
1) It seems every operating system may support it's own selection of PIDs, no two the same ? I currently have the 'pleasure' of working with OS 09381344.
2) Regarding the calc_pids.txt, what should the name of the file and location be for V8 ? Here are some options I seem to have available, assuming this file should not go under "C:\Program Files (x86)\EFILive\V8"
a) C:\Users\xxxx\Documents\EFILive\V8\User Defined Cax8
b) C:\Users\xxxx\Documents\EFILive\V8\User Defined PIDs
c) C:\Users\xxxx\Documents\EFILive\V8\Config\UserCalc ulatedPids.ini
d) C:\Users\xxxx\Documents\EFILive\V8\Config\PIDs
3) I also assume any calculated PIDs defined in the "calc_pids.txt" will only work if all the dependent PIDs are available in the operating system in use.
4) I'm also trying to log WBO2 from an Innovate LM2 through the EFILive external inputs. Oddly enough I see voltage on the Innovate output wires, but when plugging them into the EFILive V2 input (AD1) I see no data on the AD1 PID ? Any thoughts as to what I'm doing wrong ?
A quick note for the E38....
I tried this some time ago with the E38, but we are missing the DYNAIRTEMP PID. I found you can get get very close with the following though....
"({SAE.RPM}/120)*({E38.APCYL_DMA}*8)"
This uses the ECM's existing Air/Cylinder figure which should factor in the air temp corrections. I'd think that the LS1 controller would be able to use a similar equation.
Simon.
I use it quite a lot to cross reference the VE table and the MAF and it helps point out things like reverberation.
Simon, good point.Originally Posted by swingtan
E38.APCYL_DMA is the ECM/PCM computation of VE[g*K/kPa]/DAT[K]*MAP[kPa], and probably includes some internal adjustments/corrections.
LS1B equivalents of this are GM.DYNCYLAIR and GM.DYNCYLAIR_DMA.
LS1B also computes the equivalent airflow GM.DYNAIR, we could simply use this diectly, i.e. MAF = {GM.DYNAIR}.
We should probably experimentally log/calculate the following to see how they compare:
MAF1 = {GM.VETABLE_DMA.VE}/{CALC.DAT.K}*{SAE.MAP.kPa}*{SAE.RPM}/15
MAF2 = {GM.DYNCYLAIR_DMA}*{SAE.RPM}/15
MAF3 = {GM.DYNAIR}
It seems that possibly the PCM may be including temperature adjustment/correction/modeling in these...
Here's a calc_pids.txt file we can use to compare MAF1, MAF2, MAF3.
Shawn,
{GM.DYNAIRTMP_DMA.C}+273.15 now appears in too many calcpids, so it may be simpler to give it its own calc pid, see CLC-00-273.
Oh, I just thought of something! If E38.APCYL_DMA is "VE[g*K/kPa]/DAT[K]*MAP[kPa]", then we should be able to reverse the equation to create a calc-pid for the actual charge temp.
RE: comparing the tables, I've done this in the E38....
Green=MAF Airflow.
Turquoise=ECM Calculated Airflow (AIRPERSEC)
Purple=Calc PID based off DYNCYLAIR and RPM.
A closeup of the airflow after the first big throttle close.
Again, it's E38 based but the theory should hold true for LS1 as well.
Simon.
Simon, there's two (significant) wrinkles to your scheme:
1. airflow is based on air charge temp, which depends on bias, which depends on airflow--the sort of relationship that gives psychotic calculus teachers a mental boner. The best way around it I found is to assume that the estimated airflow DMA is close enough, and that due to the nature of the underlying function behind bias, small imprecisions in the estimated airflow wont make that much of an impact on the resulting bias, and thus airflow. So I use that to calc bias, then use bias to do temp, and then airmass/airflow. It's not perfect, but it works very well, comparatively to the other errors involved (especially on the fuel side, without us having a full fuel mass model and the full data set that it requires).
2. If you can solve for temp, you could solve for bias, which would be hugely useful. However, if you're trying to solve for VE/GMVE, and BIAS at the same time, you end up with one equation and two unknowns. Not exactly pretty to solve, especially on the newer ECU's where you got speed in the mix to make BIAS is a 3d function, and then you go the lag filter table that works on some unknown time unit, making it a bloody nightmare. It is doable tho, just fugly.
One experiment I've been trying to get to for years but haven't yet, is using the airflow equations for MAF and SD as each other's constraints. Let me explain: MAF is a smooth 3rd order poly. GMVE is a (mostly) smooth quadratic surface. So I think you could solve for either's MAF's poly cooefficients using GMVE surface parameters as a constraint, or vice versa. Or maybe treat them as simultaneous equations, with airflow/airmass as the common term? Or maybe just set the two airmass models equal to each other, and do an optimization minimizing the sum of error square, using AFRwb and AFRcommanded as the terms to compare? So many (horribly time consuming) ideas, so little time....
If you really want to get insight into the dichotomy between MAF and SD, generate their airmass estimations, and plot them against each other. Then do a residual analysis, and try to pinpoint for which conditions for which the big residuals happen, and you will learn why the formula that weighs MAF/SD's inputs in the hybrid model is the way it is...
Simon, that's a very good observation, good insight
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