NefMoto

Technical => Tuning => Topic started by: ABCD on July 31, 2013, 07:58:59 PM



Title: Conversion of AFR to Bosch narrowband sensor voltage (usvkl...)
Post by: ABCD on July 31, 2013, 07:58:59 PM
How can one convert actual AFR to Bosch narrowband sensor voltage (usvkl...).

For example:
If AFR is 14.7 then this voltage is 450 mV
With increase in AFR, this voltage increases and vice versa.
But what would be exact voltage for fuels with diff AFR, like ethanol blend, Gaseous fules etc.


Title: Re: Conversion of AFR to Bosch narrowband sensor voltage (usvkl...)
Post by: Milka on August 01, 2013, 01:07:21 AM
Are you trying to replace your existing pre cat 02s or just be able to log WB 02s through the post cat 02s?  Or event better run WB 02s in pre cat locations and send the narrow band emulated signal to the pre cat sensor harness and a WB signal to your post cat sensor harness?  All are possible, have you read this thread? http://nefariousmotorsports.com/forum/index.php?topic=3731.0title= (http://nefariousmotorsports.com/forum/index.php?topic=3731.0title=)


Title: Re: Conversion of AFR to Bosch narrowband sensor voltage (usvkl...)
Post by: pablo53 on August 01, 2013, 01:32:04 AM
How can one convert actual AFR to Bosch narrowband sensor voltage (usvkl...).

For example:
If AFR is 14.7 then this voltage is 450 mV
With increase in AFR, this voltage increases and vice versa.
But what would be exact voltage for fuels with diff AFR, like ethanol blend, Gaseous fules etc.

Voltage would be the same at stoich afr for whichever fuel you are using, and follow the same pattern you describe for rich/lean.

If you want to use narrow bands to tune, its a bad idea.   If you don't care that it's a bad idea, then shoot for around 900mv on boost, and make note that ITS A BAD IDEA.


Title: Re: Conversion of AFR to Bosch narrowband sensor voltage (usvkl...)
Post by: phila_dot on August 01, 2013, 05:41:54 AM
It's a lambda sensor and lambda is not fuel specific, but narrowband sensors are only accurate at lambda 1.

What are you trying to do?

You could use LALIUSH for reference.


Title: Re: Conversion of AFR to Bosch narrowband sensor voltage (usvkl...)
Post by: ABCD on August 01, 2013, 07:51:37 PM
It's a lambda sensor and lambda is not fuel specific, but narrowband sensors are only accurate at lambda 1.

What are you trying to do?

You could use LALIUSH for reference.

I want to run my vehicle with ethanol25%.
That's right about sensor not being fuel specific. but why are narrowbands accurate only for 450mV, are they designed for 14.7 AFR.


Title: Re: Conversion of AFR to Bosch narrowband sensor voltage (usvkl...)
Post by: Milka on August 01, 2013, 08:17:15 PM
Yes, narrow band ecus use the narrow band 02 sensors for closed loop (i.e. Lambda=1) control during idle, partial load.  They are not used for closed loop fueling during WOT and should not be used for WOT fueling tuning.  Get yourself a wideband sensor if you want accurate AFR readings during WOT.


Title: Re: Conversion of AFR to Bosch narrowband sensor voltage (usvkl...)
Post by: NOTORIOUS VR on August 02, 2013, 05:55:32 AM
I want to run my vehicle with ethanol25%.
That's right about sensor not being fuel specific. but why are narrowbands accurate only for 450mV, are they designed for 14.7 AFR.

No they are designed for Lambda = 1, which is the same for ALL fuels.  Oxygen sensors do no read for fuel specific, neither to ECU's.  They all read lambda and not AFR Gasoline.


Title: Re: Conversion of AFR to Bosch narrowband sensor voltage (usvkl...)
Post by: phila_dot on August 02, 2013, 06:18:45 AM
I want to run my vehicle with ethanol25%.

KRKTE

Might require larger injectors as well depending on application.


Title: Re: Conversion of AFR to Bosch narrowband sensor voltage (usvkl...)
Post by: overspeed on August 06, 2013, 07:38:21 AM
Just only a few ECU reads the value of narrowband sensors, tipically they use it as a limit, upside 450mV it´s rich and in closed loop ECU decrease lambda steps (STFT - LTFT), when it goes low then 450mV became to increase lambda steps agains

So the value is not considered...

Some new Multec fuelflex systens in Brasil are closed loop all the time, in this case it converts mV in some lambda value...you can enrich the misture and after 2 pass in dinamometer the moisture goes all to 750mV agains untill rev limiter.


Title: Re: Conversion of AFR to Bosch narrowband sensor voltage (usvkl...)
Post by: ABCD on August 06, 2013, 09:13:47 PM


...you can enrich the misture and after 2 pass in dinamometer the moisture goes all to 750mV agains untill rev limiter.

I did not quite get you.


Title: Re: Conversion of AFR to Bosch narrowband sensor voltage (usvkl...)
Post by: Lobuziak on August 09, 2013, 01:56:10 AM
Here's an article about narrowband O2 sensor -> http://www.innovatemotorsports.com/resources/news3.php and graph of it's voltage characteristics -> http://www.innovatemotorsports.com/resources/images/n32.jpg
It's characteristics is highly dependant on EGT. So it could be usable taking into account estimated EGT value.

Regards
Lobuziak


Title: Re: Conversion of AFR to Bosch narrowband sensor voltage (usvkl...)
Post by: overspeed on August 09, 2013, 05:16:46 AM
I did not quite get you.

These newer delphi ECUs works with 2 narrowband sensors and closed loop even in WOT...You enrich and it adapt back to lambda =1 again all the way.


Title: Re: Conversion of AFR to Bosch narrowband sensor voltage (usvkl...)
Post by: NOTORIOUS VR on August 09, 2013, 06:19:55 AM
All of you are going off topic and confusing the OP