WBO2-Tuning Spreadsheet

[dzidaV8]

Hi Dave, I'm wondering why are you filtering only closed loop data for WBO2 corrections? It doesn't make sense to me, as BLMs will change WB readout in CL.

[dave w]

Hi Dave, I'm wondering why are you filtering only closed loop data for WBO2 corrections? It doesn't make sense to me, as BLMs will change WB readout in CL.

I use WBO2 data from open loop AE and PE when the computer locks the BLM's to 128. CL WBO2 data will validate the corrections to the VE tables for rich or lean BLM's. A VE table causing rich or lean BLM's will also cause rich or lean WBO2 data in CL. BLM corrections have a limited ability to correct for rich or lean conditions. I've tuned several vehicles with AFR's. The WBO2 tuned vehicles run better, have fewer emissions, and achieve better MPG using CL WBO2 data.

dave w

[dzidaV8]

I've always disabled CL when tuning with WB to prevent BLMs messing up the calculations. I've never thought about doing it in CL but I guess it can make sense. By the way, some ECMs still use BLM corrections in PE, but only when BLM>128

[MAC]

Firstly let me say thanks to everyone for contributing to this thread. I am working through this and making changes to my tune.

I am trying to understand what I am actually doing and where this will get me. I think that this spreadsheet will help get my VE tables “correct”. It does this by using WBO2 readings when:

1. The computer is in closed loop
2. The computer is in open loop AND the BLM=128

The spreadsheet finds areas where the tune is not at stoich and then either adds or subtracts from the VE% table. This will subsequently add or subtract fuel to move everything towards stoich.

Is what I said above correct? Please set me straight if I am wrong.

My expectation is that I will end up with a tune that looks something like the attached picture. But I could be wrong.

afrtable.GIF

So my biggest question is this:

• I do not understand how this process will get me to a tune that looks like the attached picture because it seems like this process is moving everything towards stoich.

BTW – I set the spreadsheet to 14.1 because all of the gas around me is E10.

Thanks,

MAC

[dave w]

There is a string of "Average IF" in the spreadsheet.

Average If, = Closed Loop
Average IF PE, = False
Average IF AE, = False

BLM's are not used and are Completely disregarded.

BLM's above 128 are lean.
BLM's below 128 are rich.

Increasing the VE table cell value (for example 2400 RPM, 70KPa) 68 to 78 will lower the AFR ratio (for example 15.2 AFR down to maybe 14.6 AFR, just guessing here to illustrate what will typically happen). Likewise if the BLM averages where 138 and changing the cell valve from 68 to 78 the BLM average will lower to 133, again just guessing.

PE is filtered to Average IF, PE = Active

To actually achieve 14.1, the Narrow Band O2 sensor voltages will need to be adjusted in the chip, which I've never done. The Narrow Band O2 sensor voltages are attempting to correct BLM's to 128 or 14.7.

I would first get the AFR's close to 14.7, then tweak the Narrow Band O2 sensor voltage to get the BLM's for E10 AFR.

Quite often BLM's and AFR's will contradict each other.

I like tuning with AFR, because the engine will run better than tuning with BLM's!

dave w

[De-stroker]

There is a string of "Average IF" in the spreadsheet.

Average If, = Closed Loop
Average IF PE, = False
Average IF AE, = False

BLM's are not used and are Completely disregarded.

BLM's above 128 are lean.
BLM's below 128 are rich.

Increasing the VE table cell value (for example 2400 RPM, 70KPa) 68 to 78 will lower the AFR ratio (for example 15.2 AFR down to maybe 14.6 AFR, just guessing here to illustrate what will typically happen). Likewise if the BLM averages where 138 and changing the cell valve from 68 to 78 the BLM average will lower to 133, again just guessing.

PE is filtered to Average IF, PE = Active

To actually achieve 14.1, the Narrow Band O2 sensor voltages will need to be adjusted in the chip, which I've never done. The Narrow Band O2 sensor voltages are attempting to correct BLM's to 128 or 14.7.

I would first get the AFR's close to 14.7, then tweak the Narrow Band O2 sensor voltage to get the BLM's for E10 AFR.

Quite often BLM's and AFR's will contradict each other.

I like tuning with AFR, because the engine will run better than tuning with BLM's!

dave w

[MAC]

Hoping that it is okay for me to post these things here and that other folks new to tuning can learn from this. If I am out of bounds, mods feel free to delete/move.

1. Will I be "done" with this part of tuning once I have everything in blue for "near idle no PE/AE" and "off idle no PE/AE"?
2. I am surprised that my injector DC is so low. I upgraded the fuel pump. Pressure is around 13 psi. Does this chart (photo) "make sense" to you guys with lots of experience?Injector DC.jpg
3. I am getting a lot of knock. How "bad" is this? How to I make it go away? (see picture)knock.jpg
4. I am getting lots of spark advance at low RPM and high kPa. What does this mean? spark advance.jpg
5. I am very surprised at how much I have decreased VE compared to the stock tune. Again does this "look right"? Could it be related to upgraded fuel pump? Picture shows the difference between the stock BIN and my current tune. VE Tuned vs Stock.PNG
6. Last but not least I thought I would share my current WBO2 map from the spreadsheet. Got a long way to go. Comments welcome. Off Idle WBO2.jpg

Thanks,
AC