AFR Reported in ST

drfrink24 · 08-03-2005, 12:14 PM

My understanding is that front O2 sensor cannot read anything below 14.7:1. So, when you see various values in the logs richer than 14.7:1, are these the targets then? If not, then, are they just off by random (or, predicable) figures?

**WolfPlayer** · 08-03-2005, 12:20 PM

What you heard isn't correct ... well, sort of.

Normal O2 sensors are only really accurate around 14.7:1. However, the front O2 sensor on our cars isn't a normal O2 sensor. It is a near wideband sensor that is accurate a couple points away from 14.7:1. The factory O2 and my wideband seem to agree till somwhere in the 12's (IIRC) when going to the rich side of the spectrum. The ECU outputs the AFR in the datastream for troubleshooting purposes. The ECU doesn't shut down this data stream element in situations where it isn't accurate. It really doesn't care ... it keeps outputting the data. Thus, the value in the datastream isn't a target ... it is the real AFR that is calculated in the ECU based on input from the front O2 sensor. It's just not accurate once it gets too rich or too lean. However, for an O2 sensor ... it's pretty good.

t

drfrink24 · 08-03-2005, 01:18 PM

As always wolf, very helpful.

Been meaning to ask, where does your username come from?

**WolfPlayer** · 08-03-2005, 01:46 PM

Quote:

Originally Posted by drfrink24

As always wolf, very helpful.

Been meaning to ask, where does your username come from?

Wolfenstein - Enemy Territory. The default name is (was?) 'WolfPlayer' if you didn't choose a name. I was heavily involved in ET clan-based stuff for awhile. Now I'm just chilling and not gaming as much ... but I still do love me some PC gaming. I'll probably jump back into it after the 'itch' comes back. I just needed a break because I was gaming too much ... well, not too much from a geek standpoint but too much from a family perspective.

t

drfrink24 · 08-03-2005, 03:57 PM

Yeah, I was 99% sure thats where it came from. Great game, considering it was free. Too many friggen air strikes though, kinda killed it for me.

If you want to get re-addicted, try the Battlefield 2 demo. Very fun, much improved over the previous version (Battlefield 1942). Nothing like manning a chain gun on a blackhawk over an enemy camp...

Could this possibly be the most off topic post in a technical forum???

daemon · 08-03-2005, 06:52 PM

I might date myself, but anyone else remember playing the original Castle Wolfenstein? Back in the days of the Apple II and the Commodore 64? Life was much simpler back then.

drfrink24 · 08-03-2005, 07:10 PM

Oh yeah. Buddy had it on his Apple. IIRC, you could get a nazi to hold his hands up sitting at a desk, and then shoot him, he'd fall face down on the desk.

**WolfPlayer** · 08-03-2005, 09:35 PM

Long live off-topic posts

t

R4ND0M_AX3 · 08-04-2005, 08:49 AM

I remember you had to pick the locks on the C64 version.

"Haus Pass"

***Horhay*** · 08-30-2005, 02:02 PM

back on topic for a tick, how do I get the ST to show AFR in the ratio form instead of voltage?

Christian. · 08-30-2005, 02:08 PM

Quote:

Originally Posted by Horhay

back on topic for a tick, how do I get the ST to show AFR in the ratio form instead of voltage?

Are you talking about A/F ratio instead of Lambda in the Primary Fuel table?

If you notice that the values in the Boost Targets table are displayed in metric units or bar and you would prefer that the table values are displayed in standard units of psi; the first thing you will need to do is go to the Edit drop down menu and select Configure Options.

For the short-cut keys for these steps, you can also hold down the Ctrl key and hit the F key at the same time.

Then you will scroll to the right using the mouse courser and select the Display tab.

On the Display tab, check the box labeled “Use Standard Units?” then click on the “OK” button located at the bottom right of the Options Menu.

Now notice how the values in the Boost Targets table have changed from metric units measured in bar to standard units measured in psi, or pounds per square inch.

Selecting this display option will change the units of measurement for all tables in the software from metric to standard units.

Another example of this change will be present in the Primary Fuel table.

These units will change from Lambda to units of A/F or air fuel ratio.

Make sense?

daemon · 08-30-2005, 02:08 PM

I assume you mean instead of lambda form? That isn't a voltage, but a ratio compared to stoich. Go into the configuration under the Display tab and select "Use Standard Units".

edit: darn you're fast today Christian.

***Horhay*** · 08-30-2005, 02:36 PM

Im talking about when I datalog and on the dashboard. Is it because I don't have a wideband 02 sensor? Maybe Im confused, but in reading other threads, I got the understanding that I could use my stock front 02 sensor up to a point. When I datalog it comes out in what appears to be a voltage reading from the sensor. That could be that we (my friend was reading the screen while I was driving) hadn't changed the display option previously. I'll report back. Thanks.

daemon · 08-30-2005, 02:45 PM

It will log using the same units set in the display config. A touch confusing, but that's life.

In the log it is also lambda, not volts if you are not using standard units.

***Horhay*** · 08-30-2005, 07:39 PM

you guys rock, im a newb! thanks

08-03-2005, 12:14 PM	#1
drfrink24 Junior STI Driver Car: JBP 04 WRX STi Posts: 197 IWSTI Addict since: May 2004 Trader Rating: (0)	AFR Reported in ST My understanding is that front O2 sensor cannot read anything below 14.7:1. So, when you see various values in the logs richer than 14.7:1, are these the targets then? If not, then, are they just off by random (or, predicable) figures? This ad is not endorsed by this member. Please register or login to hide this ad.

08-30-2005, 07:39 PM	#15
*Horhay* Unobtanium Member Car: 2005 CGM STi Fav Mod: Process West V-Mount IC Location: 1st state Posts: 979 IWSTI Addict since: Dec 2004 Trader Rating: (6)	you guys rock, im a newb! thanks This ad is not endorsed by this member. Please register or login to hide this ad.

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08-03-2005, 12:20 PM	#2
WolfPlayer Moderator & ECU Tech Car: 05 CGM STI Fav Mod: mo boostaz Location: Fredneck, MD Posts: 3,759 IWSTI Addict since: Jun 2004 Trader Rating: (6)	What you heard isn't correct ... well, sort of. Normal O2 sensors are only really accurate around 14.7:1. However, the front O2 sensor on our cars isn't a normal O2 sensor. It is a near wideband sensor that is accurate a couple points away from 14.7:1. The factory O2 and my wideband seem to agree till somwhere in the 12's (IIRC) when going to the rich side of the spectrum. The ECU outputs the AFR in the datastream for troubleshooting purposes. The ECU doesn't shut down this data stream element in situations where it isn't accurate. It really doesn't care ... it keeps outputting the data. Thus, the value in the datastream isn't a target ... it is the real AFR that is calculated in the ECU based on input from the front O2 sensor. It's just not accurate once it gets too rich or too lean. However, for an O2 sensor ... it's pretty good. t

08-03-2005, 01:18 PM	#3
drfrink24 Junior STI Driver Car: JBP 04 WRX STi Posts: 197 IWSTI Addict since: May 2004 Trader Rating: (0)	As always wolf, very helpful. Been meaning to ask, where does your username come from?

08-03-2005, 03:57 PM	#5
drfrink24 Junior STI Driver Car: JBP 04 WRX STi Posts: 197 IWSTI Addict since: May 2004 Trader Rating: (0)	Yeah, I was 99% sure thats where it came from. Great game, considering it was free. Too many friggen air strikes though, kinda killed it for me. If you want to get re-addicted, try the Battlefield 2 demo. Very fun, much improved over the previous version (Battlefield 1942). Nothing like manning a chain gun on a blackhawk over an enemy camp... Could this possibly be the most off topic post in a technical forum???

08-03-2005, 06:52 PM	#6
daemon The Next Petter Solberg Car: 2004 STi Location: Florida Posts: 894 IWSTI Addict since: Feb 2004 Trader Rating: (0)	I might date myself, but anyone else remember playing the original Castle Wolfenstein? Back in the days of the Apple II and the Commodore 64? Life was much simpler back then.

08-03-2005, 07:10 PM	#7
drfrink24 Junior STI Driver Car: JBP 04 WRX STi Posts: 197 IWSTI Addict since: May 2004 Trader Rating: (0)	Oh yeah. Buddy had it on his Apple. IIRC, you could get a nazi to hold his hands up sitting at a desk, and then shoot him, he'd fall face down on the desk.

08-03-2005, 09:35 PM	#8
WolfPlayer Moderator & ECU Tech Car: 05 CGM STI Fav Mod: mo boostaz Location: Fredneck, MD Posts: 3,759 IWSTI Addict since: Jun 2004 Trader Rating: (6)	Long live off-topic posts t

08-04-2005, 08:49 AM	#9
R4ND0M_AX3 Grassroots STI Racer Car: 05 Subaru WRX STi Fav Mod: Cobb StreetTUNER Location: Elk Grove, CA USA Posts: 590 IWSTI Addict since: Jul 2004 Trader Rating: (0)	I remember you had to pick the locks on the C64 version. "Haus Pass"

08-30-2005, 02:02 PM	#10
*Horhay* Unobtanium Member Car: 2005 CGM STi Fav Mod: Process West V-Mount IC Location: 1st state Posts: 979 IWSTI Addict since: Dec 2004 Trader Rating: (6)	back on topic for a tick, how do I get the ST to show AFR in the ratio form instead of voltage?

08-30-2005, 02:08 PM	#12
daemon The Next Petter Solberg Car: 2004 STi Location: Florida Posts: 894 IWSTI Addict since: Feb 2004 Trader Rating: (0)	I assume you mean instead of lambda form? That isn't a voltage, but a ratio compared to stoich. Go into the configuration under the Display tab and select "Use Standard Units". edit: darn you're fast today Christian.

08-30-2005, 02:36 PM	#13
*Horhay* Unobtanium Member Car: 2005 CGM STi Fav Mod: Process West V-Mount IC Location: 1st state Posts: 979 IWSTI Addict since: Dec 2004 Trader Rating: (6)	Im talking about when I datalog and on the dashboard. Is it because I don't have a wideband 02 sensor? Maybe Im confused, but in reading other threads, I got the understanding that I could use my stock front 02 sensor up to a point. When I datalog it comes out in what appears to be a voltage reading from the sensor. That could be that we (my friend was reading the screen while I was driving) hadn't changed the display option previously. I'll report back. Thanks.

08-30-2005, 02:45 PM	#14
daemon The Next Petter Solberg Car: 2004 STi Location: Florida Posts: 894 IWSTI Addict since: Feb 2004 Trader Rating: (0)	It will log using the same units set in the display config. A touch confusing, but that's life. In the log it is also lambda, not volts if you are not using standard units.