how-to: control closed loop AFR with your wideband O2 system
Sep 24, 2008, 06:19 PM
#32
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well it seems were back in the same place I started, tweaking the formula again to adjust for ground offset by changing from 9.6 to 9.4 gets me as close as I can get.
I guess its good enough for controlling closed loop cruise but not ideal for serious tuning.
I guess its good enough for controlling closed loop cruise but not ideal for serious tuning.
Sep 24, 2008, 06:59 PM
#34
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I used that formula but on average the reading was high by .2 throughout the entire log. I lowered the offset to 9.4 which has made the readings more accurate. Must be because of ground offset.
Sep 24, 2008, 07:11 PM
#35
You used this formula eval="((x*0.01895)*2)+9.6"and it was still off by .2AFR?? Thats odd, according to your entirrrre log it should be dead on for the most part. Can you do another log using that formula so I can take a look? I did notice oddball spots where it was off as much as .7AFR but thats where the analog noise and EMF comes into play.
Sep 24, 2008, 07:25 PM
#36
If you look at dudical26's first AFR log that he posted, there is no consistent offset between the serial out AFR and the analog out AFR as read by the ECU. In general, it looks as if the analog out lags slightly behind the serial out. At any rate, the formula that dudical26 is using looks to be the best for his setup.
Sep 24, 2008, 07:32 PM
#37
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Do you guys think this would be close enough for use in replacing front and rear 02 signal?
When I tune I will use serial logging though. The analog feed will be convenient when we are finally able to log with openport 2.0 then I can log AFR to SD card without a lappy
When I tune I will use serial logging though. The analog feed will be convenient when we are finally able to log with openport 2.0 then I can log AFR to SD card without a lappy
Sep 25, 2008, 06:23 AM
#40
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Last night I got the ZT2 pretty darn close to the serial......let me know if you think something is off or im doing something wrong.
I used (19.6-9.6)/255 = .03922
Plugged it in as .03922*x + 9.6....it was about .1 afr off so I change the 9.6 to 9.7 and its very close. Final equation was .03922*x + 9.7, I have mine grounded to the metal shroud behind the glove box where the ecu is.
I am within .1-.2 at cruise which to me is more than fine....so tonight I will plug in the ML/BL and see how she works. Thanks for all the help guys....
This would be what I plug in, correct?
ML, 1/.03922 = 25.5
BL/ML, 9.7/.03922 = 247.32
I used (19.6-9.6)/255 = .03922
Plugged it in as .03922*x + 9.6....it was about .1 afr off so I change the 9.6 to 9.7 and its very close. Final equation was .03922*x + 9.7, I have mine grounded to the metal shroud behind the glove box where the ecu is.
I am within .1-.2 at cruise which to me is more than fine....so tonight I will plug in the ML/BL and see how she works. Thanks for all the help guys....
This would be what I plug in, correct?
ML, 1/.03922 = 25.5
BL/ML, 9.7/.03922 = 247.32
Sep 25, 2008, 08:00 AM
#42
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Yeah that's what I have always done (even with the LC-1)....I use the serial cable to tune with and check if i want a accurate reading. I use the analog for wideband control and when im to lazy to plug the serial in and just want to ball park where I am AFR wise......
Sep 25, 2008, 10:05 AM
#44
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Just tried it during lunch......car starts fine, starts to idle at 14.7 then immediately goes leaner and leaner.....it went to 20.1 and the car started to die so I shut it off, will just flash back to stock O2.
I dont understand? Im using the linear wire....the #'s log fine when comparing the analog to serial on the stock front O2, very close.
But something is missing to make this work....cause its not working
Here is the linear graph from zietronix website: http://www.zeitronix.com/Products/zt...bandoutput.htm
I dont understand? Im using the linear wire....the #'s log fine when comparing the analog to serial on the stock front O2, very close.
But something is missing to make this work....cause its not working
Here is the linear graph from zietronix website: http://www.zeitronix.com/Products/zt...bandoutput.htm
Last edited by travman; Sep 25, 2008 at 11:11 AM.
Sep 25, 2008, 12:43 PM
#45
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how long did it take for the car to go from 14.7 to 20?
I know that the zeitronix will not spit out any readings for the first 30 seconds while it "warms up" wonder if this is causing an issue during startup?
I know that the zeitronix will not spit out any readings for the first 30 seconds while it "warms up" wonder if this is causing an issue during startup?