When you guys log block 031 for O2 voltages do you look at...

Swank4 · 07-18-2005, 10:44 PM

the "Pre TWC" column or the "Post TWC"? Also, are B1 and B2 supposed to be the same or very near each other?

I'm hitting 0.90 - 0.91 on the "Post TWC" but "Pre" never gets above 0.86. Wondering if the Lemmi tweaking is excessive.

If anyone wants to see some logs let me know.

PSmalls::DoggieStyle · 07-18-2005, 10:52 PM

I've seen a few cars that have the 2 pre-cat sensors ~.01 volts off at every data point. As long as they follow the same pattern, it should be okay. I'd be willing to take a look at your logs. FWIW, you probably don't want to run mid .8s on 91 craptane (you are in CA and running 91 octane IIRC). You would probably benefit from a richer mixture like .88-.89 pre-cat 02 sensors on that crappy of gas.

Swank4 · 07-18-2005, 11:01 PM

PSmalls::DoggieStyle · 07-18-2005, 11:03 PM

Tweaking using 02 voltages isn't the most scientific method ever. In simple terms, you need more protection against detonation with lower octanes. Personally, I'd feel safe in mid .8s on higher octane. I currently am in the .845-.865 range on 94 octane FWIW, but really only because I'm maxing out my stock injectors. Once I upgrade injectors, I'll be sure to play around with different voltages to find the sweet spot on my car. Every car seems to like it a little different.

EdyJun · 07-19-2005, 12:05 AM

Can any one tell me why O2 dips and then comes back up?

PSmalls::DoggieStyle · 07-19-2005, 12:08 AM

Imolavirus@BuehnEngineering · 07-19-2005, 07:58 AM

EdyJun · 07-19-2005, 11:17 AM

Here is another one. You can see the O2 sensors dip and then come back up. It does that on all of my logs. (Some more than others)

Can some one explain how the Boost effects the O2 sensor (I know more boost = more air but doesn't the ECU add more fuel for that?)

O2

MAF and IGN

Boost

Imolavirus@BuehnEngineering · 07-19-2005, 02:31 PM

your boost log looks fine. What is your exact setup and boost settings?

On your O2 graph, is the right or left y-axis the precat O2 voltages?

EdyJun · 07-19-2005, 02:41 PM

Car is Bone STOCK. i have to check on the left and right axle. i will let u know.

07-18-2005, 10:44 PM	#1
Swank4 AudiWorld Super User Garage is empty, add now Join Date: Aug 2002 Location: San Francisco Posts: 6,764	When you guys log block 031 for O2 voltages do you look at... the "Pre TWC" column or the "Post TWC"? Also, are B1 and B2 supposed to be the same or very near each other? I'm hitting 0.90 - 0.91 on the "Post TWC" but "Pre" never gets above 0.86. Wondering if the Lemmi tweaking is excessive. If anyone wants to see some logs let me know.

07-18-2005, 10:52 PM	#2
PSmalls::DoggieStyle Elder Member Garage is empty, add now Join Date: Jan 2004 Posts: 30,257	Pay attention to pre-cat sensors. The 2 pre-cat sensors should read very close, if not exactly same. I've seen a few cars that have the 2 pre-cat sensors ~.01 volts off at every data point. As long as they follow the same pattern, it should be okay. I'd be willing to take a look at your logs. FWIW, you probably don't want to run mid .8s on 91 craptane (you are in CA and running 91 octane IIRC). You would probably benefit from a richer mixture like .88-.89 pre-cat 02 sensors on that crappy of gas.

07-18-2005, 11:01 PM	#3
Swank4 AudiWorld Super User Garage is empty, add now Join Date: Aug 2002 Location: San Francisco Posts: 6,764	Thanks. If running higher octane are lower volts (leaner) OK? What range?

07-18-2005, 11:03 PM	#4
PSmalls::DoggieStyle Elder Member Garage is empty, add now Join Date: Jan 2004 Posts: 30,257	It's hard to put a specific voltage range with certain octanes, etc... Tweaking using 02 voltages isn't the most scientific method ever. In simple terms, you need more protection against detonation with lower octanes. Personally, I'd feel safe in mid .8s on higher octane. I currently am in the .845-.865 range on 94 octane FWIW, but really only because I'm maxing out my stock injectors. Once I upgrade injectors, I'll be sure to play around with different voltages to find the sweet spot on my car. Every car seems to like it a little different.

07-19-2005, 12:05 AM	#5
EdyJun AudiWorld Super User Garage is empty, add now Join Date: Dec 2002 Posts: 2,719	Re: Pay attention to pre-cat sensors. The 2 pre-cat sensors should read very close, if not exactly s Can any one tell me why O2 dips and then comes back up? __________________ 2000 Audi S4 STG 3 FATS = 3.66 w/ 91 oct AIM: EdyJun 11 September 2001 In their honor. In their memory. <font color="red">---------------------------------------------------------- <u><big> <a href="http://homepage.mac.com/edyjun1/S4/index.htm">EdyJun's S4 Directory (FAQ, DIY, Info, Tips and Help) </a> </big> </u>---------------------------------------------------------- </font>

07-19-2005, 12:08 AM	#6
PSmalls::DoggieStyle Elder Member Garage is empty, add now Join Date: Jan 2004 Posts: 30,257	Shift?

07-19-2005, 07:58 AM	#7
Imolavirus@BuehnEngineering AudiWorld Super User Garage is empty, add now Join Date: Mar 2002 Posts: 17,943	if you didn't shift, what did your boost curve look like? __________________ -Jacob ^^^CLICK SIG FOR BUEHN ENGINEERING WEBSITE^^^ <big><big>Website Here!!!</big></big> <big>Items For Sale</big>

07-19-2005, 11:17 AM	#8
EdyJun AudiWorld Super User Garage is empty, add now Join Date: Dec 2002 Posts: 2,719	NO shifting, it was a 3rd gear pull. (Logs inside) Here is another one. You can see the O2 sensors dip and then come back up. It does that on all of my logs. (Some more than others) Can some one explain how the Boost effects the O2 sensor (I know more boost = more air but doesn't the ECU add more fuel for that?) O2 MAF and IGN Boost __________________ 2000 Audi S4 STG 3 FATS = 3.66 w/ 91 oct AIM: EdyJun 11 September 2001 In their honor. In their memory. <font color="red">---------------------------------------------------------- <u><big> <a href="http://homepage.mac.com/edyjun1/S4/index.htm">EdyJun's S4 Directory (FAQ, DIY, Info, Tips and Help) </a> </big> </u>---------------------------------------------------------- </font>

07-19-2005, 02:31 PM	#9
Imolavirus@BuehnEngineering AudiWorld Super User Garage is empty, add now Join Date: Mar 2002 Posts: 17,943	Well, at 4K is where you had the dip in O2 voltages, and at that point your boost log looks fine. What is your exact setup and boost settings? On your O2 graph, is the right or left y-axis the precat O2 voltages? __________________ -Jacob ^^^CLICK SIG FOR BUEHN ENGINEERING WEBSITE^^^ <big><big>Website Here!!!</big></big> <big>Items For Sale</big>

07-19-2005, 02:41 PM	#10
EdyJun AudiWorld Super User Garage is empty, add now Join Date: Dec 2002 Posts: 2,719	Re: Well, at 4K is where you had the dip in O2 voltages, and at that point Car is Bone STOCK. i have to check on the left and right axle. i will let u know. __________________ 2000 Audi S4 STG 3 FATS = 3.66 w/ 91 oct AIM: EdyJun 11 September 2001 In their honor. In their memory. <font color="red">---------------------------------------------------------- <u><big> <a href="http://homepage.mac.com/edyjun1/S4/index.htm">EdyJun's S4 Directory (FAQ, DIY, Info, Tips and Help) </a> </big> </u>---------------------------------------------------------- </font>

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