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Fink_tha_Audi
01-16-2009, 06:49 PM
Today logged some data, I have an AEB engine, so the channels I used were 2, 31, 3. Ch. 31 gave me o2 sensor values in voltage how do I convert/analyze that to A/F ratio? Do I need to log some more data in a different channel.

Quattro
01-16-2009, 11:39 PM
go to audiworld, they have a vag com tech section. Sorry I mentioned AW!

Or go to ross tech wiki site, I believe they have some ways to convert it.

Fink_tha_Audi
01-17-2009, 11:56 AM
go to audiworld, they have a vag com tech section. Sorry I mentioned AW!

Or go to ross tech wiki site, I believe they have some ways to convert it.

Thanks

GetBoosted84
01-17-2009, 12:32 PM
http://www.audigeeks.com/forums/index.php?topic=561.0

Fink_tha_Audi
01-17-2009, 03:32 PM
According to audigeeks it seems that Im getting some thing different.
Channel 31: Lambda Reading or A/F Ratio

This value is particularly important to be viewed and interpreted only when the car is under full throttle input as lifting up on the throttle will result in funky numbers. Take your log in third gear (or higher if your local authorities will allow) from 2500rpm or so until redline. The values you will see are: "1” = 14:1 ratio, ".85” = 12:1 ratio, ".75” = 10:1 ratio. A car that runs 14:1 (lambda value of about .95) all the way up to redline on increased boost is running a bit lean. Conversely, a car that is running 11:1 (lambda value of about .80) from idle to redline is running a bit rich. Remember that lean is your ultimate enemy. Running too lean for too long will spell disaster for the motor. It is ok for making power, but it is not ok for protecting the turbo and motor from failure. Ideally you would like to see the A/F pass linearly from the factory 14.7:1 at idle towards 13:1 in the mid rpms (3500rpm or so) to at least 12:1 at redline. This would show a car that is getting good fuel mileage under easy driving, but richens up nicely as you wind it out under full throttle to redline. This would make you feel at ease driving the car under high load conditions at high speeds (freeway cruising at 120mph) or using the car for frequent track days.

This would be nice:

RPM Lambda
2500 .99
2750 .95
3000 .95
3250 .95
3500 .90
3750 .90
Here is a sample:
'031
O2 Sens Bef TWC O2 Sens Aft TWC
Voltage Voltage
V V
0.03 0.16
0.825 0.65
0.82 0.65
0.84 0.665
0.045 0.65
0.84 0.665
0.83 0.665
0.78 0.59
0.665 0.255
0.77 0.59
0.81 0.61
0.85 0.665
0.78 0.65
0.045 0.31
0.035 0.16
0.065 0.16
0.56 0.575
0.83 0.665
0.035 0.33
0.05 0.18
0.08 0.5
0.67 0.59
0.48 0.575
0.745 0.61
0.095 0.46
0.705 0.5
0.12 0.515
0.515 0.535
0.605 0.535
0.09 0.2
0.65 0.235
0.215 0.515
0.715 0.61
0.7 0.61
0.665 0.59
0.135 0.535
0.27 0.575
0.325 0.59
0.67 0.575
0.825 0.63
0.025 0.2
0.855 0.63
0.83 0.685
0.625 0.665
0.055 0.555
0.065 0.5
0.83 0.685
0.045 0.125
0.115 0.105
0.68 0.575
0.63 0.535
0.855 0.725
0.085 0.14
0.11 0.46
0.11 0.215
0.54 0.575
0.625 0.61
0.665 0.29
0.29 0.105
0.675 0.59
0.62 0.575
0.09 0.235
0.085 0.085
0.7 0.61
0.09 0.555
0.115 0.555
0.015 0.76
0.1 0.045
0.645 0.665
0.105 0.63
0.59 0.61
0.15 0.575
0.23 0.59
0.27 0.65
0.095 0.59
0.665 0.59
0.295 0.65