Are o2 # always reliable?

evil666

Active Member
Joined
Dec 4, 2004
The reason I want to know if 02 # are reliable is because I run 30 lbs tomco fuel injectors and I have been told that they are to small for my set up, which everyone who has told me that is probably right. The thing is that I monitor my 02 sencor with the otc 4000e and my 02 # are 870-880 at 24 lbs of boost and I only get 1 to 3 KR and this is on pump fuel and ethanol. I want to know could it be possible that the 02 # are good but that the car could still be running lean somehow? Am I still safe using these injectors or should I upgrade imediately or could it wait?

Thanks for any info Marco.

86 Grand National t-top (59900km)
stock long block,stock suspension, red stripe convertor, te44, smc alk injection, 24lbs boost, 94 octane, hooker cat back with dyno max ultra flow muffers, tomco 30lbs injectors, dynotech stage 4 street chip, thdp, mease 24 row IC, Ron Custom max boost brake module, MT drag radials (275/50/15) 3800lbs race weight with driver.
BEST E/T
60FT=1.52
1/8= 7.38
I/4= 11.74
MPH=113 Best MPH=114
 
evil666 said:
The reason I want to know if 02 # are reliable is because I run 30 lbs tomco fuel injectors and I have been told that they are to small for my set up, which everyone who has told me that is probably right.

The stock O2 is only good for telling richer or leaner then 14.7:1.
That's all it was designed to do, and that's all it can do.
Asking for more from it then that is playing Russian Roulette.

The reason WB's exist, is because the stockers, just can't do the job.

I've run back to back passes, while tuning with a WB, and have seen a 810mv, stock reading, actually be anywhere from 11.2 -> 12.5. That IMO, is just too much of an error to ignore.

For the $300 or so bucks that they cost now, they're more expensive to *not have*. In the days of $1,200+ WBs, is when they got the reputation of being useful since everything else was so expensive.
 
evil666 said:
The reason I want to know if 02 # are reliable is because I run 30 lbs tomco fuel injectors and I have been told that they are to small for my set up, which everyone who has told me that is probably right. The thing is that I monitor my 02 sencor with the otc 4000e and my 02 # are 870-880 at 24 lbs of boost and I only get 1 to 3 KR and this is on pump fuel and ethanol. I want to know could it be possible that the 02 # are good but that the car could still be running lean somehow? Am I still safe using these injectors or should I upgrade imediately or could it wait?

Thanks for any info Marco.

86 Grand National t-top (59900km)
stock long block,stock suspension, red stripe convertor, te44, smc alk injection, 24lbs boost, 94 octane, hooker cat back with dyno max ultra flow muffers, tomco 30lbs injectors, dynotech stage 4 street chip, thdp, mease 24 row IC, Ron Custom max boost brake module, MT drag radials (275/50/15) 3800lbs race weight with driver.
BEST E/T
60FT=1.52
1/8= 7.38
I/4= 11.74
MPH=113 Best MPH=114

One VERY important fact that escapes almost all OTC4000 users is that it uses a different point of reference than virtually ALL other scan tools we routinely use. When comparing your 870-880 readings, you would be seeing 770-780's on any of the other scan tools we use. You have to subtract 100mv from your reading to get a more realistic reading of actual O2's.

With that turbo and your setup, I'd be willing to bet a six pack your injectors are WAY in excess of 120% duty cycle when you're up on full boost.
 
Hi Bruce, what are you using to monitor your o2 #, because I want to know if your 02 means 910's on my otc4000e. Like Turbo Dave said, the otc read 100mv more than other scan tools. What are good and safe numbers to run on a wideband on our turbo buicks? I heard you should run up to 11.8 to
play it safe, is this correct?

Thanks,
Marco

86 Grand National t-top (59900km)
stock long block,stock suspension, red stripe convertor, te44, smc alk injection, 24lbs boost, 94 octane, hooker cat back with dyno max ultra flow muffers, tomco 30lbs injectors, dynotech stage 4 street chip, thdp, mease 24 row IC, Ron Custom max boost brake module, MT drag radials (275/50/15) 3800lbs race weight with driver.
BEST E/T
60FT=1.52
1/8= 7.38
I/4= 11.74
MPH=113 Best MPH=114
 
evil666 said:
Hi Bruce, what are you using to monitor your o2 #, because I want to know if your 02 means 910's on my otc4000e. Like Turbo Dave said, the otc read 100mv more than other scan tools. What are good and safe numbers to run on a wideband on our turbo buicks? I heard you should run up to 11.8 to
play it safe, is this correct?

Thanks,
Marco

86 Grand National t-top (59900km)
stock long block,stock suspension, red stripe convertor, te44, smc alk injection, 24lbs boost, 94 octane, hooker cat back with dyno max ultra flow muffers, tomco 30lbs injectors, dynotech stage 4 street chip, thdp, mease 24 row IC, Ron Custom max boost brake module, MT drag radials (275/50/15) 3800lbs race weight with driver.
BEST E/T
60FT=1.52
1/8= 7.38
I/4= 11.74
MPH=113 Best MPH=114


I built my own WB for the GN...
However, when I'm looking at someone else's car, I have a LM-1. It's be reliable, and has been in a number of good, and poor running cars without a hiccup.

Each car is rather picky about what makes it happy, I;ve seen some that like 12.3:1 at WOT, and others at 10.8:1. Mid 11's should be a relatively safe place to begin. BUT, a WB is just one tool, you want to watch the Knock Sensor, and look at the plugs to get a full view of what's going on.
 
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