Tuning with the stock O2

[Bruce]

What do the stock O2 numbers mean?
Here's a data log with the oem O2 sensor, and a WB.

Please look closely.
At 10.4-10.6 AFR, it can read from 623->819 mv.
Then at ~ 12.4, from 465->783

TimeStamp: 12/09/2004 - 10:41:41

Run Mph Rpm Map VE% Tps CTS MAT O2 Sa Rt DC% AFR rrWB
:47 0 2000 102 88 60 171 95 628 28 0 12 12.5 10.5
:47 4 2050 102 87 61 171 95 783 28 0 13 12.5 10.4
:47 4 2125 104 85 61 171 86 819 29 0 13 12.5 10.6
:47 4 2175 105 83 63 171 86 757 29 0 13 12.5 11.7
:47 7 2275 109 81 63 171 86 650 29 0 14 14.7 12.8
:47 8 2325 110 80 63 171 86 633 29 0 14 12.5 12.6
:47 12 2375 113 79 63 171 86 704 30 0 14 12.5 12.8
:47 12 2425 115 79 63 171 86 562 30 0 15 12.5 13.1
:47 12 2475 116 80 63 171 86 646 30 0 16 12.5 13.2
Run Mph Rpm Map VE% Tps CTS MAT O2 Sa Rt DC% AFR rrWB
:48 12 2550 119 81 63 171 86 761 30 0 17 12.5 13.1
:48 15 2625 123 82 63 171 86 650 27 2 18 12.5 13.0
:48 13 2700 125 83 63 171 86 473 27 2 19 12.5 12.9
:49 33 3500 198 80 46 171 77 504 21 2 40 12.5 12.9
:49 35 3550 205 80 52 171 77 465 20 2 42 12.5 12.5
:50 37 3700 228 80 74 171 77 597 14 4 50 12.5 12.2
:50 39 3725 232 80 74 171 77 606 14 4 51 12.5 12.8
:50 40 3750 234 80 74 171 77 757 14 4 53 12.5 13.0
:50 40 3775 234 80 74 171 77 513 15 4 54 12.5 12.5
:50 41 3850 236 80 74 171 77 633 14 4 55 12.5 12.6
:50 42 3875 237 80 74 171 77 606 15 3 56 12.5 12.6
:50 44 3925 238 80 74 171 77 690 15 3 56 12.5 12.4
:50 45 3950 238 80 74 171 68 580 15 2 57 12.5 12.6
:50 46 4000 239 80 74 171 68 513 15 2 57 12.5 12.5
Run Mph Rpm Map VE% Tps CTS MAT O2 Sa Rt DC% AFR rrWB
:51 47 4050 239 80 74 171 68 650 15 2 59 12.5 12.8
:51 47 4050 241 80 74 171 68 549 15 2 59 12.5 12.6
:51 48 4050 241 80 74 171 68 735 12 6 60 12.5 12.4
:51 49 4050 242 80 74 171 68 730 13 5 60 12.5 12.3
:51 49 4100 243 80 74 171 68 655 13 5 61 12.5 12.1
:51 51 4100 243 80 74 171 68 664 13 4 61 12.5 12.3
:51 52 4150 243 80 74 171 68 491 13 4 62 12.5 12.2
:51 53 4175 244 80 74 171 68 513 14 4 62 12.5 12.2
:51 53 4225 244 80 74 171 68 584 14 4 63 12.5 12.7
:51 55 4300 246 80 74 171 68 509 14 3 65 12.5 12.1
:53 66 3575 247 80 73 169 68 473 3 14 54 12.5 12.4

Your call on what you'll consider safe.

[granitestategn]

Bruce,

You've been doing some great work. If you find yourself with nothing to do, how about EGT vs. WB O2?? The correlation between factory O2 and WB O2 isn't to good, eh? I'd like to pick up a WB O2 but my wife has put a moratorium on GN spending 'til next year. :dong:

[Bruce]

Bruce,
You've been doing some great work. If you find yourself with nothing to do, how about EGT vs. WB O2?? The correlation between factory O2 and WB O2 isn't to good, eh? I'd like to pick up a WB O2 but my wife has put a moratorium on GN spending 'til next year.

The stock sensor isn't worth more the figuring out stoich, IMO. It was never designed to do anything other then *switch* from rich to lean at 14.7.

I'm hoping to get to where I can data log EGT but so far, I can't.
There's just so many other things to do. And with the way my scanners are put together, adding another channel while possible takes alot of time. Like in the case above, the WB is wired into the ecm, the conversion done for AFR, done in the ecm, and then sent out in the ALDL data stream. Any it's done differently then the *normal* syclone patch was done to do that.

Now, that I have the basic scanner covered, there's a few other things I want to be able to data log also. Just need more time......

At least next year is only ~3 weeks away. :)

[BJM]

I couldn't make sense of the text with proportional spacing.

[gnjones231]

For what it's worth.....

Here is a plot of Bruce's data showing RPM, TP, and O2. Looks to be something wrong here.

[gnjones231]

Here is a plot of Bruce's data showing RPM and MPH. Something is wrong here too. Isn't the tranny supposed to shift sometime?

[gnjones231]

Here is some data I took on my car many years ago. Ignore the red graph labeled A/F ratio...it is no good. This is the stock O2 sensor in the stock location. Data is taken with a one of a kind, High Speed Synchronous Datalogger that is capable of taking data at 500 frames/second ( a frame consists of about 40 seperate piece of data).

HTH

Dave

[Bruce]

For what it's worth.....
Here is a plot of Bruce's data showing RPM, TP, and O2. Looks to be something wrong here.

Nothing's wrong there, there were some bad packets, in the data log.
The purpose of this thread is comparing the WB to a NBs output

[Bruce]

Here is a plot of Bruce's data showing RPM and MPH. Something is wrong here too. Isn't the tranny supposed to shift sometime?

There were some bad packets in the data log.
This thread is about WBs to NBs.

If you look at the 48, and 49 sec data frames, you can see there are just a few valid packets in that area.

[Bruce]

Here is some data I took on my car many years ago. Ignore the red graph labeled A/F ratio...it is no good. This is the stock O2 sensor in the stock location. Data is taken with a one of a kind, High Speed Synchronous Datalogger that is capable of taking data at 500 frames/second ( a frame consists of about 40 seperate piece of data).
HTH
Dave

Without having a reference of what the commanded or actual AFRs are, it just shows the O2s output. It shows the O2 voltages dropping during the run, which leaves one to further wonder what was going on. Was the car leaning out, boost increasing, EGT skewing the O2, coolant temp changing, MAT temp change, etc..

In my log, you'll note that it shows the MAT, Commanded, and Actual, so you know the calibration was running close to what was expected. Not to mention that by including the K/Pa, one could see the cal was close over the entire K/Pa, MAT, CTS, VSS, ranges.

I have to seriously edit down the material to make it *readable* when posting, but suffice to say, the BL/Int, commanded, and actual closed loop numbers also all line up. So while working at ~14.7 the NB is fine, it's not to be relied upon, at least IMO, for more then the roughest of estimates of AFRs at other then close to Stoich..

Now that WB are so resonably priced risking engine damage, due to AFR errors, just seem not to be cost effective, again, IMO..