Been a while but i have a question about wot tuning

[Aint Skeered]

i went to the track the other night with my trans am and made a pass with the wideband hooked up. Running throught the gears the car is seeing 14.1 /1 af and commanding 12.56
i changed stoich from 14.63 to 14.12 since i have e10 in the tank.
the a/f dropped to 13.1 but now commanding 11.9

both passes were in shitty weather and street trim and ran 117.63 mph.
After i left the track i was running in 5th gear and hammer the gas while watching the wideband and it is 12.2/1 commanding 11.9
Which should i go by, the banging throught the gears or like a dyno , one gear all the way through as even 4th gear from a roll shows almost dead on what im commanding.

[WeathermanShawn]

What type of tune are you running? I.E. SD, MAF, Closed or Open-Loop etc.

While most of us see some some variation(s) of AFR per gear, I usually try to tune AFR for the main drive gears (M6) 3rd & 4th..

In my tune CLMAFSD Hybrid most of my airflow modeling follows the MAF. WOT is pretty dead accurate in all drive gears. My only problem might be in 5th or 6th gear Overdrive and nailing it. That is such a low MAF Frequency, that it is sometimes hard to tune for both Closed-Loop and PE Mode when they 'share' the same frequency.

I guess what I am trying to say, is that my AFR does not vary by the amount you are describing. In your case I would tune for the 'leanest' gear and live with being rich in the others. But, I will stick with the premise that if you are off by more than .5 AFR per gear, something is amiss in the tune.

[swingtan]

Usual response... Post the log and the tune.

Chances are that the E10 is messing with the fueling a bit. Her in Aus, E10 is very, very close to 98RON ULP in terms of power, but you really need to tune for it. the issues are that it does have a slightly different stoich. ratio and it also has a different evaporation factor. This will upset dynamics to some degree, so banging through the gears might look pretty ordinary. With an M6, you need to watch the finer points of fueling as it can really effect the shifts.

Simon

[Aint Skeered]

I am running a closed loop maf tune. I will have to wait untill im on my laptop to post the tune and log.
When i seen it was very lean i did added fuel to try to get me through the night at the track by dropping the injector flow rate at 0 vac and it brough it closer.
I know its not proper way but when your at the races you do what you have to.
I plan to take it to the dyno and tune it right for wot
With Stoich changed to 14.12 , i noticed on the drive home that almost always i was -1 -2 on the o2's.
so the driveabilaty part is good.
just wot , the car showed lean.

[WeathermanShawn]

Even though E10 is rampant across the U.S., I never really saw the need to make a lot of the changes that have been rampantly debated on this board and elsewhere. The problem is that the gas is blended up to 10% Ethanol and sometimes contains other oxygenates. It seems like an endless chase, but I never see any drift in LTFT's or Commanded AFR's in my portion of the U.S. As noted, you may have to do even more fine-tuning to compensate.

While I understand your race technique of manipulating MANVAC, of course that will not address part-throttle detonation. That can occur and cause as much engine damage as WOT, and just as quickly. So, when you get it on the dyno it is all about the MAF Freq vs airflow. WOT tuning is relatively easy, but it pays to do several WOT runs in differing gears if that is an issue.

Good luck.

[joecar]

Did you program the E10 stoich value into your wideband...?

If that is not possible, then you have to use lambda from the wideband.

[Aint Skeered]

Even though E10 is rampant across the U.S., I never really saw the need to make a lot of the changes that have been rampantly debated on this board and elsewhere. The problem is that the gas is blended up to 10% Ethanol and sometimes contains other oxygenates. It seems like an endless chase, but I never see any drift in LTFT's or Commanded AFR's in my portion of the U.S. As noted, you may have to do even more fine-tuning to compensate.

While I understand your race technique of manipulating MANVAC, of course that will not address part-throttle detonation. That can occur and cause as much engine damage as WOT, and just as quickly. So, when you get it on the dyno it is all about the MAF Freq vs airflow. WOT tuning is relatively easy, but it pays to do several WOT runs in differing gears if that is an issue.

Good luck.

part throttle is fine, ltft's stay around -1 to -3
wot is where i fooled with manvac, just to get it to fatten up for the track. i get no knock retard either .
Joe car, i did not mess with my wideband. did not know i had to , may go back to 14.63 for stoich and try getting it dialed in that way.

[Aint Skeered]

also, going off of my Nova on the track and the dyno it likes 12.2/1 as i run e10 in it.
I am basing my readings off of my avalanch. I refuel at the same station and my avalanch ethenol sensor allways seems to stay on the 10% reading.

[joecar]

Your wideband is able two report either of these:
- lambda (regardless of fuel type/blend).
- AFR based on stoich AFR programmed into wideband.

AFR is simply lambda scaled for stoichiometric AFR.

For example, your wideband is probably programmed for stoich being at 14.7... so you need to reprogram it for 14.12... the LC-1 is easy to program, I don't know about others.

A better solution is to forget about AFR, and use a calc pid for lambda from the wideband, and to define a BEN calc pid that uses this lambda.

For example, the LC-1:

The presupplied AFR pid is defined as: CALC.LC11_AFR = {EXT.AD1}*3 + 7.35 <-- this is based on stoich being 14.7

So now, dividing both sides by 14.7 gives: CALC.LC11_LAMBDA = {EXT.AD1}*0.204082 + 0.5

And the BEN pid would now be: CALC.BEN_LC11 = {GM.EQIVRATIO}*{CALC.LC11_LAMBDA} <-- this is now more accurate for two reasons


And if necessary you can define some calc pids for displaying AFR from GM.EQIVRATIO and CALC.LC11_LAMBDA.

[joecar]

i.e. lambda is the ratio of air:fuel relative to the stoichiometric ratio of air:fuel regardless of fuel being used... and this is what the wideband is really reporting (not AFR).

[joecar]

Continuing from post #9:

So you would be working in Lambda and EQR from now on...

You can define calc pids to display GM.EQIVRATIO and CALC.LC11_LAMBDA in AFR form (for mental convenience) like this:


What is your B3601...?

for gasoline it should be 14.63, so then:
CALC.AFR_CMD_E0 = 14.63/{GM.EQIVRATIO}
CALC.AFR_WBO_E0 = 14.63*{CALC.LC11_LAMBDA}

for E10 it should be 14.12, so then:
CALC.AFR_CMD_E10 = 14.12/{GM.EQIVRATIO}
CALC.AFR_WBO_E10 = 14.12*{CALC.LC11_LAMBDA}

what should it be for E85...?

You would use these for display convenience only... all your tuning would be done with lambda and EQR.

[Aint Skeered]

Joe are these pids already in there ? i have no clue about making pids. I will look at it this week when im off the boat. ( not home at the time)

[joecar]

We can make you some pids... give me a day or two (or anyone feel free to jump in).

[Aint Skeered]

great, then i may need help getting them in the program. I have been away for quite some time and now my memory has failed me.

[joecar]

No worries.

[WeathermanShawn]

Skee:

Are you using Analog or Serial Connection for your wideband. I have the CALC. PIDS (plagiarized) for serial using 14.63 AFR as EQ=1.

Is that what you needed or something more specialized?

[Aint Skeered]

im using serial with black box logging. It has been a long time since i took an update on it.

[WeathermanShawn]

I had to stare at these PIDS for three days straight (WO2) before it clicked. I think I finally understand the entire wideband stoich vs B3601 relationship etc.

Someone should probably do a Quality Control check on these PIDS..I guess it all depends on what you finally determine B3601 should be..:confused:..

[joecar]

The calc pid that Shawn posted above (see post #16) will work...

- goto folder My Documents\EFILive\V7.5\User Configuration,
- rename the existing calc_pids.txt to calc_pids.txt-saved,
- copy the new calc_pids.txt to this folder,
- start the scantool,
- goto pids tab,
- see if these new pids show up.

When you run E10, replace 14.628573 with 14.12 in the calc_pids.txt file (use Notepad to edit, then save file, exit Notepad).

When you run E0 (gasoline), put value back to 14.628573 or 16.6286.

Or, you can add extra pids for 14.12.

[ but remember that these AFR pids are for viewing pleasure... you will use the BENS1 pid for adjusting VE/MAF tables ]

Do the same with B3601, set it to 14.6286 or 14.12, and flash to PCM (cal-only flash).

[joecar]

Here's a calc_pids.txt with AFR_E00 (14.63) and AFR_E10 (14.12)...

when you change gasoline, edit B3601 in your calibration, and use the right AFR pid (for viewing).

For VE/MAF table correction, use the BENS1 pid.