two big $EE questions

**steveo** · 06-12-2015

played with this theory today:

1. 'maf disable' (already commonly known, and labeled as 've enable')
2. what robert theorized is a 've enable' flag at bit 7@0x2029 allows both lookups to be used (how exactly what the calculation is or its weight is unknown)

all factory bins have both flags UNSET meaning that if it's true, maf disable being set will obviously use VE lookup anyway (otherwise we'd be running n-alpha or car wouldn't run)

the stock f-body MAF table on my car hits blm trims of 116-120 @ low RPM, and 130-134 at higher airflow (the whole table wants to be tiled a bit). my adjusted MAF table runs blm trims 124-128.

my VE table is narrowband tuned, has been painstakingly detailed until it was perfect. i've been running speed density for a month now and my trims are always 122-126.

first test: stock flags (unset unset) and crank VE. i set 10% VE flat. car started and idled ok. suprisingly the car ran ok, but during acceleration and decelleration it felt REALLY WEIRD. maybe it was the butt dyno, but throttle response was dead. this leads me to believe that some fueling events are influenced by VE regardless of these flags, but cruising range seems unaffected.

next test: run my modified VE table with a stock MAF calibration with both lookups enabled. as my calibrated VE table is 8-10% lower at low airflows, my trims should be higher than they'd be without the flag set.

results: running 've enable' without 'maf disable' (theoretically using both tables for lookup all the time) brought my trims at lower airflows to 128-132. that's a BIG difference, leading me to believe in this mode that VE is heavily weighted. the biggest thing was that it seemed really stable, like the trims were a bit on the high side, but there were no spikes or dips.

next test, set 30% VE across the board with 've enable' flag set. result, engine started and kinda idled, but bucked and died under throttle. i shut it off before it had a chance to hit closed loop.

tried calibrated VE table but a bullshit MAF table, 2% airflow. car barely ran for a few secs then died. this confirms that the maf is being used.

so this tells me that we can run a proper hybrid MAF/VE fueling mode, cool stuff

im going to develop a tune in this mode and see how the results are vs. pure speed density or a re-cuved MAF table.

**steveo** · 06-12-2015

report on trim averages using a calibrated VE table with a stock MAF table with 'both lookups enabled', stock maf table, and calibrated VE table (but the VE table sure was never this close before!)

Code:

**** Narrowband Trim vs RPM vs MAP ****
(Igoring cells with counts < 6)
    0    10    20    30    40    50    60    70    80    90
   0
     ....  ....  ....  ....  ....  ....  ....  ....  ....  ....
 400
     ....  ....  ....  ....  ....  ....  ....  ....  ....  ....
 800
     ....  ....   129   127   126  ....  ....  ....  ....  ....
1200
     ....  ....   129   128   127   128  ....  ....  ....  ....
1600
     ....   128   128   127   126   128  ....  ....  ....  ....
2000
     ....   127   127   126   126   128  ....  ....  ....  ....
2400
     ....   125   126   126   126   127   128  ....  ....  ....
2800
     ....   125   126   125   125   128  ....  ....  ....  ....
3200
     ....  ....  ....  ....  ....  ....  ....  ....  ....  ....

vs airflow:

Code:

**** Narrowband Trim vs MAF AFGS ****

  MAF AFGS    TRIM    MULT    COUNT
   0 -   5     128   0.996    757
   5 -  10    ----   -----    0
  10 -  15     128   1.000    895
  15 -  20     127   0.994    1405
  20 -  25     126   0.987    633
  25 -  30     126   0.985    260
  30 -  35     126   0.982    158
  35 -  40     126   0.986    103
  40 -  45     125   0.978    37
  45 -  50     126   0.984    36
  50 -  55     127   0.989    21
  55 -  60     126   0.988    19
  60 -  65    ----   -----    6
  65 -  70     128   0.999    12
  70 -  75     127   0.995    11

p.s. does anyone want me to port my analyzer to windows?

**bybyc5** · 06-14-2015

Nice work! As I mentioned earlier, I have honestly never tuned my VE tables figuring they were only a backup if my MAF died. I will add this to my list of things to do in my next tune for my car. Albeit your above process is a bit over my head, I do get the gist of it. This I would like to better understand, and realize trial and error ( mostly error!!

) is how it's done. Just how would one use your analyzer?

I actually found a copy of ve master in my old win xp pro laptop, and my datamaster license is tied to that laptop. Wonder how good or not ve master will work with my setup. The cam is not that radical and driveability is really OK for even for a manual trans car like mine, however I do have a mystery rich condition at part throttle steady cruise at 2000 rpm. Above that is good. Strange to that according to the cam profile, that is where the cam starts to make power.

**steveo** · 06-14-2015

however I do have a mystery rich condition at part throttle steady cruise at 2000 rpm.

is the maf reading too much air? (maybe there's a point of really nasty reversion with that cam around 2k?) or are the o2s getting sketchy readings and messing up closed loop in that region?

try and read your logs and look for sketchy sensor readings around that area. for example unstable looking MAF readings can point to intake reversion and pulsation screwing up readings, or weird looking o2 behavior (where closed loop can't seem to stabilize) can point to corrupt o2 readings at that point. for example;

my last lt1 had a point around 20 g/s of maf flow during cruise, the maf would read increased airflow and dump a ton of fuel. but if you monitored MAP and MAF around that range, you'd see it was all over the place, and that it was just the cam causing totally non-linear airflow at that point and confusing things.

my current lt1 had a point under very light loads 1500rpm where it usually trimmed lean and added fuel. but, if you read a log, you see that the o2s are totally insane at that point, i chalked it up to a point where the cam is just doing nasty things and you get totally non-linear exhaust flow.. once i took CORRCL and made it much weaker during that range of airflow, it mostly went away.

im sure you can tune it out

Just how would one use your analyzer?

pretty much do a ton of datalogging and export as CSV format (tunerpro and tunercat can both do that), then just configure the software so it knows what your column names are

there are spreadsheets for doing VE tuning too that work great, but the reason i coded one instead is its a lot of copy/paste and i find results end up better if you use LOTS of logging.

with spreadsheets, or even with history tables in tunerpro, you have to parse and sort all your logs and pick ranges to play with, which is fine for throwing a couple logs in, but my static analyzer is smart enough to do things like reject records with 'timestamps < x' or 'coolant temp < y' or 'pe enabled = yes' depending on what it's analyzing, so you can just throw it a month worth of logs and you get good results with no effort.

if i port it to windows, will you help test it?

**bybyc5** · 06-14-2015

Sure thing. I would like that, however I am not a code writing person, and would require some coaching. I am not an avid user of excel either, so this may be tiresome for you. If you have the patience to coach, I have the desire to learn.

Not sure if this is jacking the thread though. Maybe move this to a new thread, or emails?

I don't currently have my wide-band set up to data log. I just have a live digital display that can read back hi and low for like a 1/4 mile run, etc. So I will need to set up an input for TunerPro from My LC-1 controller. I'll dig out my Instructions that came with it and get that set up. I have my stock narrow band O2's in use as well.

My current laptop is running Windows 7 pro. The other older laptop ( Win XP Pro ) mentioned earlier is usable if need be, but my current Win 7 laptop is what I have TunerPro already installed on and would prefer using it.

**steveo** · 06-15-2015

making new thread

**jthompson122183** · 06-26-2015

in the latest tunercat ecm ee defintion i came across some new stoich afr and egr enable coolant stuff and added it to your eex

any chance of getting a copy of your latest eex?
Attachment 9143

**steveo** · 06-26-2015

you mean tunercat has a new definition out with different stoich AFR variables than the ones we already found?

here's the current version, sorry i haven't posted it to my website yet.

someone should really poke around on that stoich thing. i could test it out a bit, but i only run pure gasoline here so i'd be a bad candidate.

**jthompson122183** · 06-26-2015

yes sir just got their ecm file yesterday...and started difference a factory tunes against itself but with things changed one at time. Then i used tunerpro to difference the files.

**kur4o** · 06-26-2015

Can you post the starting address of the TC stoich AFR to take a look.
Thanks.

**jthompson122183** · 06-26-2015

Originally Posted by kur4o

Can you post the starting address of the TC stoich AFR to take a look.
Thanks.

sure, 0x140D2 and 0x1417E

**kur4o** · 06-26-2015

0x140D2 is used to calculate Overheat AFR

The formula is (Byte_40D2=14.7) - [(Coolant - byte_28df) * byte_28e0] = Overheat AFR
if lower than (byte_28e1=Overheat afr value)

0x1417E is used to calculate Power Enrichment AFR value only. It is the base value that PE correction are made to.

These are not connected with the other 4 stoich targets and can be changed and be different If you need them.
The first 4 stoich targets need to be changed at the same time and have same value in hex, otherwise they won`t work.

**jthompson122183** · 06-26-2015

Originally Posted by kur4o

0x140D2 is used to calculate Overheat AFR

The formula is (Byte_40D2=14.7) - [(Coolant - byte_28df) * byte_28e0] = Overheat AFR
if lower than (byte_28e1=Overheat afr value)

0x1417E is used to calculate Power Enrichment AFR value only. It is the base value that PE correction are made to.

These are not connected with the other 4 stoich targets and can be changed and be different If you need them.
The first 4 stoich targets need to be changed at the same time and have same value in hex, otherwise they won`t work.

tc just has them as stoich1 and stoich2 in the constants menu. I seen that they where undefined in the eex so I brought to you guys attention.