2nd Generation Specific (1986-1992) 1986-1992 Discussion including performance modifications and technical support sections.
Sponsored by:

what do nb o2 voltages mean?

Thread Tools
 
Search this Thread
 
Old 02-28-11, 01:11 AM
  #1  
What am I doing...

Thread Starter
iTrader: (2)
 
Mr.Cool's Avatar
 
Join Date: Jul 2009
Location: Toronto
Posts: 481
Likes: 0
Received 0 Likes on 0 Posts
what do nb o2 voltages mean?

how do i read narrow band o2 voltages? i have an rtek 2.0 so i can see the voltages but what do they mean? how can i tell when im near stoich?

i know there really **** but i need to make due with it till i get a wideband.
Old 02-28-11, 06:14 AM
  #2  
Rotary Freak
 
HAILERS2's Avatar
 
Join Date: Jul 2008
Location: FORT WORTH TEXAS
Posts: 1,660
Likes: 0
Received 1 Like on 1 Post
A car with a disabled airpump or ACV....................will read about 0.8 at idle which is RICH.

A normal reading at idle is 0.7/0.8 and not to be worried about that and don't try to lean it out. Normal.

Lean would be in the 0.1 to 0,4.

ECU going in to closed loop while driving above 1700 rpm would show a rapidly changing reading above and below 0.4. Hard to read since it will move so fast up and down.
Old 02-28-11, 06:21 AM
  #3  
Rotary Revolutionary

iTrader: (16)
 
sharingan 19's Avatar
 
Join Date: May 2006
Location: Jacksonville, Tampa & Tallahassee
Posts: 3,881
Received 2 Likes on 2 Posts
So basically, don't try to tune w/ a narrowband because unless you are idling or in closed loop its not giving u any useful information.

Get a wideband before you do something you regret.
Old 02-28-11, 09:22 AM
  #4  
What am I doing...

Thread Starter
iTrader: (2)
 
Mr.Cool's Avatar
 
Join Date: Jul 2009
Location: Toronto
Posts: 481
Likes: 0
Received 0 Likes on 0 Posts
ok makes sense. so its not just the really bad accuracy but the closed loop makes it imposable to tune with.

are aem widebands good i like the way they look but iv heard there a bit slower to respond is it really bad should i consider something else?
Old 02-28-11, 10:41 AM
  #5  
Moderator

iTrader: (3)
 
j9fd3s's Avatar
 
Join Date: Mar 2001
Location: https://www2.mazda.com/en/100th/
Posts: 30,832
Received 2,603 Likes on 1,847 Posts
Originally Posted by Mr.Cool
ok makes sense. so its not just the really bad accuracy but the closed loop makes it imposable to tune with.
that is kind of the point of closed loop, you dont NEED to tune there, because the O2 sensor is doing it for you.

to tune in that region you actually need to disable closed loop.
Old 02-28-11, 11:17 AM
  #6  
What am I doing...

Thread Starter
iTrader: (2)
 
Mr.Cool's Avatar
 
Join Date: Jul 2009
Location: Toronto
Posts: 481
Likes: 0
Received 0 Likes on 0 Posts
so is it a bad idea to tune there? wouldnt you be able to achieve better power by tuning there? so whats the real point to a wideband it cant only be just for under 1700rpm.

and if it is a good i idea to tune there then how do you disable closed loop?

Last edited by Mr.Cool; 02-28-11 at 11:20 AM.
Old 02-28-11, 11:28 AM
  #7  
Rotorhead

 
Evil Aviator's Avatar
 
Join Date: Feb 2001
Location: Charlottesville, Virginia, USA
Posts: 9,136
Likes: 0
Received 39 Likes on 33 Posts
Originally Posted by Mr.Cool
ok makes sense. so its not just the really bad accuracy but the closed loop makes it imposable to tune with.
Good tuners can use the narrowband just fine. The trick is that you need to know what you are doing because there is more to tuning than trying to match a number that you read on the internet. This also applies to wideband gauges, but they are a little easier for a novice to use because they are more accurate and less affected by temperature changes. Also, O2 sensors are intended for tuning the engine for idle and cruise rather than for performance. Contrary to what the wideband gauge vendors advertise, the wideband gauge will not magically turn a novice into a professional tuner. If you don't know what you are doing, then I recommend that you either have a professional tune your engine or that you take a tuning course at your local tech school. Your local professional tuner will have his own tuning equipment, so there should be nothing extra for you to buy other than his labor. Tuning is not something that you can learn well by reading a book or internet forums. Experimenting on your expensive engine isn't such a great idea IMO.
Old 02-28-11, 11:43 AM
  #8  
What am I doing...

Thread Starter
iTrader: (2)
 
Mr.Cool's Avatar
 
Join Date: Jul 2009
Location: Toronto
Posts: 481
Likes: 0
Received 0 Likes on 0 Posts
lol my "expensive" engine isnt that expensive i got it for 600 in and done its just a stock s4 keg with s5 intakes. it has a bit of the 3800 rpm lag but i tried compensating by adding 5.1% more fuel at that rpm(over kill) but now it pulls like a mother there. so im just thinking that theres more to be had and that i just dont want to lean out and blow.
Old 02-28-11, 11:53 AM
  #9  
Moderator

iTrader: (3)
 
j9fd3s's Avatar
 
Join Date: Mar 2001
Location: https://www2.mazda.com/en/100th/
Posts: 30,832
Received 2,603 Likes on 1,847 Posts
Originally Posted by Mr.Cool
so is it a bad idea to tune there? wouldnt you be able to achieve better power by tuning there? so whats the real point to a wideband it cant only be just for under 1700rpm.

and if it is a good i idea to tune there then how do you disable closed loop?
i suggest doing a little more reading on engine tuning. there is a lot of info on this site too, although it can be hard to find.

basically the car is only in closed loop between 1200-3500rpm and PART THROTTLE. over a certain throttle position and over 3500rpm it goes back into open loop again.

if you go say to foxed.ca and start reading manuals, you'll find that mazda breaks the ecu map into "ZONES" so there is an idle zone, a cruise zone (closed loop, 1500-3500rpm, part throttle), decel zone, and a high load zone. each "zone" is optimized for a different thing. the accel zone, is optimized for power, the cruise zone is optimized for low emissions and mileage.

i don't know how to disable the 02 feedback without unplugging it. it might be in the Rtek software
Old 02-28-11, 04:59 PM
  #10  
rotorhead

iTrader: (3)
 
arghx's Avatar
 
Join Date: Aug 2004
Location: cold
Posts: 16,182
Received 429 Likes on 263 Posts
Old 02-28-11, 05:06 PM
  #11  
Moderator

iTrader: (3)
 
j9fd3s's Avatar
 
Join Date: Mar 2001
Location: https://www2.mazda.com/en/100th/
Posts: 30,832
Received 2,603 Likes on 1,847 Posts
Originally Posted by arghx
lol, the red curve is scary....
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
gxl90rx7
Haltech Forum
6
06-30-17 11:30 PM
WANKfactor
1st Generation Specific (1979-1985)
6
09-29-15 01:14 PM
rattlehead
New Member RX-7 Technical
2
09-25-15 10:55 PM
The1Sun
1st Generation Specific (1979-1985)
7
09-18-15 07:13 PM
The1Sun
New Member RX-7 Technical
5
09-15-15 04:45 PM



Quick Reply: what do nb o2 voltages mean?



All times are GMT -5. The time now is 03:18 AM.