WOT
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Joined: Jul 2001
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From: SLIDELL, LA.
WOT
when scanning wot, the o2 is reading between 930-965, i know thats rich but am i unstanding you correctly that the scanner does not read wot properly and i would need a dyno for that. does that mean when i adjust the fuel pressure and go do a scan that the o2 at wot is wrong? tts scanner program.
thanks
ken
like the forum, i think it will be a hit.
thanks
ken
like the forum, i think it will be a hit.
Le Mans Master
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From: Fort Worth Texas
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Re: WOT (TOEMAN)
I used to think that 900mv at WOT was probably running rich.... but not anymore. In Diacom I was always around 900-950mv at WOT, so I leaned it out a bit, so that I was getting 850-880mv. I went to dyno yesterday and my a/f was 14.2:1 through all three runs!!! :eek:
I need to richen it back up. Alot.
These cheap $30 parts store O2 sensors just don't measure WOT very well. Every car is a little different too, but on my car, I'm not going to sweat 950mv on my O2! (It's a new Bosch unit, too)
I need to richen it back up. Alot.
These cheap $30 parts store O2 sensors just don't measure WOT very well. Every car is a little different too, but on my car, I'm not going to sweat 950mv on my O2! (It's a new Bosch unit, too)
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Joined: Jul 2001
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From: SLIDELL, LA.
Re: WOT (Marcho Polo)
so, what i am understanding is that the scanner will react to the fuel adjustment. just curious because i am just about to make a decision to install a procharger and sure would like to know if the scanner is reacting properly.
thanks
thanks
Le Mans Master
Joined: Sep 2000
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From: Bartlett IL
Re: WOT (TOEMAN)
Toeman,
As I also found out, the on-board O2 sensor is really only accurate within the stochiometric range of 14.7:1. However, maximizing WOT requires an AFR of around 12.3-12.7 depending on the motor. I ran EASE scantool during several dyno runs and found that the on-board O2 sensor registered .98v
yet the Wideband showed an AFR of 13.5-14:1. Only when the on-board was at 1.03-1.04v was the actual AFR at 12.5 or so. So you can see what just a few hundredth's of a volt mean in terms of AFR at WOT. So you really need a wideband to tell what's going on at WOT.
As I also found out, the on-board O2 sensor is really only accurate within the stochiometric range of 14.7:1. However, maximizing WOT requires an AFR of around 12.3-12.7 depending on the motor. I ran EASE scantool during several dyno runs and found that the on-board O2 sensor registered .98v
yet the Wideband showed an AFR of 13.5-14:1. Only when the on-board was at 1.03-1.04v was the actual AFR at 12.5 or so. So you can see what just a few hundredth's of a volt mean in terms of AFR at WOT. So you really need a wideband to tell what's going on at WOT.
Melting Slicks
Joined: Aug 2001
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Re: WOT (TOEMAN)
For a period of time, I attempted to tune my car based upon the O2 feedback of the factory sensors. I thought I had it dialed in fairly well. Then I put it on a dyno with data acquisition and a wideband O2.. MAJOR difference. I was so far off it wasn't funny!! Guess that's what you get for $30ea per factory sensor.. It works good enough for the ECM, but not good enough for some high performance tuning!
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From: SLIDELL, LA.
Re: WOT (Glock'94)
WELL, SINCE WE ESTABLISHED THAT THE SCANNER IS NOT RELIABLE FOR ADJUSTING THE 02, FOR RICH AND LEAN CONDITIONS, IS IT RELIABLE AND DEPENDABLE FOR THE TIMING AND RETARD READINGS???
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Le Mans Master
Joined: Mar 1999
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From: Fort Worth Texas
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Re: WOT (TOEMAN)
WELL, SINCE WE ESTABLISHED THAT THE SCANNER IS NOT RELIABLE FOR ADJUSTING THE 02, FOR RICH AND LEAN CONDITIONS, IS IT RELIABLE AND DEPENDABLE FOR THE TIMING AND RETARD READINGS???
I think those parameters are going to be reliable... it's pretty much just the O2 sensor. To get one that measures very accurately at all conditions is expensive to design-in on the Corvette. The unit widely used on FI cars these days does the job adequately, so that's why it's used. Also why GM is a little rich on WOT conditions as a safeguard since the stock O2 is not reliable in those conditions.
Melting Slicks
Joined: Apr 2001
Posts: 2,116
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From: Ca.
Re: WOT (TOEMAN)
Just some info on wide bands- check out http://www.fjoinc.com/automotive/ Their wide band now has software and the hardware to log a file to your laptop. There is still a GP on it with Steve Hayes- his e-mail is SHayes at petroferm I just got my new fjo from Steve after sending him a check-so it's safe to send him money. Unlike a guy in Bakersfield!!!! (carbedc4 aka too many to list; for those of you who didn't follow that thread!) With the GP I paid $706.00 for the complete datalog kit. It lets you log your a/f ratio, rpm and also has an input for a 0-5volt signal. (tps or your preference) Yup, it's not cheap, but I've got a complete tuning pkg now! Well, OK, not a dyno-I just don't know how I could get that one by my wife! Anybody with ideas on that, please feel free to give some suggestions. :lol:
Racer
Joined: Jun 2000
Posts: 469
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From: Norfolk VA
Re: WOT (drive it)
My O2's were flatlined at 910 mv and that ended up being 14.5 on the dyno with the wideband! 12.5 read 960mv or so on the stock O2's.
Moral to the story do not do serious WOT tuning without a dyno.
Later,
RJ
Moral to the story do not do serious WOT tuning without a dyno.
Later,
RJ