Wide Band
06-12-2009, 11:02 PM
#21
Too Much Fun
So, I am looking at installing a wideband and guage...through researching for the right setup for me I have come across DUAL Wideband sensors, 1 for each side of engine. Is this necessary? Is it going to make that much difference vs. installing just the 1 wideband 02 sensor?
06-13-2009, 10:21 AM
#22
Safety Car
Member Since: Jun 1999
Location: Austin, Singapore, Kuala Lumpur, Houston, Dallas, Hong Kong, Elgin, etc.. Texas
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So, I am looking at installing a wideband and guage...through researching for the right setup for me I have come across DUAL Wideband sensors, 1 for each side of engine. Is this necessary? Is it going to make that much difference vs. installing just the 1 wideband 02 sensor?
I would recommend a set up is to have a muffler shop weld in a bung on the passengers side before the cat and wire it into the HP Tuner's system. Keep it installed only long enough to get your tune done, remove it and plug the bung hole. Perhaps you want to install a gauge somewhere on the dash but I would think it would be a distraction. However, for my car, I just removed the NB02, installed the WB02, put the PCM in open loop, calibrated the VE table, then the MAF, copied these tables into the closed loop file, and then moved on to timing and other settings.
Really, the only real reason for installing the wide band is to recalibrate the VE and MAF tables after engine air flow modifications so the commanded A/F ratio is what you should get at WOT after PE and other modifiers. And to limit part throttle correction via the STFT, LTFT, and the other misc modifiers.
06-13-2009, 07:47 PM
#23
2nd Gear
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So you are saying that I can just simply swap (both) of my stock narrowband o2 sensors for widebands? I am not using this for tuning purposes but I would like to know if I can substitute them? I have heard that they are less supseptable to fouling? Also, I already have a wideband gauge hooked up and mounted in the car.
06-13-2009, 09:27 PM
#24
Well, you can tune your car using your technique, but I prefer using a WB02.
As you all know, a Narrow Band O2 sensors output voltage to the PCM in a very narrow range of .5 +- of the stochiometric Air fuel Ratio. If you watch the voltage output from the narrow band in closed loop, it is constantly swinging between high and low voltage. And that drives the STFT and LTFT corrections. You really can not tell with any accuracy what the actual A/F ratio is so changes you make to the MAF or VE table is nothing more than an educated guess. The closer your VE and MAF tables are, the less corrections are necessary.
Yes, you can do some limited calibration from the LTFT and STFT at part throttle, but they again are driven off the NB02. And, more importantly, at WOT you have no idea what the actual A/F ratio is since the NB02 voltage, LTFT %, and STFT all go to zero since the fueling (thus A/F ratio) is determined by the PCM based on the VE table, the PE table, the MAF table, and a few other tables thrown in for IAT, ECT, and others.
Yes, you can make adjustments at WOT based on the KR but with the narrow bands, you still have no idea if you are 10:1 or 20:1 A/F ratio. And that can change at various RPM levels.
Its kind of like cooking a steak on a BBQ grill with a thermometer. Its nice to know the actual temp is 350 degrees and not 500. With a NB02 all you know its over 350 or under 350 but not how much.
As you all know, a Narrow Band O2 sensors output voltage to the PCM in a very narrow range of .5 +- of the stochiometric Air fuel Ratio. If you watch the voltage output from the narrow band in closed loop, it is constantly swinging between high and low voltage. And that drives the STFT and LTFT corrections. You really can not tell with any accuracy what the actual A/F ratio is so changes you make to the MAF or VE table is nothing more than an educated guess. The closer your VE and MAF tables are, the less corrections are necessary.
Yes, you can do some limited calibration from the LTFT and STFT at part throttle, but they again are driven off the NB02. And, more importantly, at WOT you have no idea what the actual A/F ratio is since the NB02 voltage, LTFT %, and STFT all go to zero since the fueling (thus A/F ratio) is determined by the PCM based on the VE table, the PE table, the MAF table, and a few other tables thrown in for IAT, ECT, and others.
Yes, you can make adjustments at WOT based on the KR but with the narrow bands, you still have no idea if you are 10:1 or 20:1 A/F ratio. And that can change at various RPM levels.
Its kind of like cooking a steak on a BBQ grill with a thermometer. Its nice to know the actual temp is 350 degrees and not 500. With a NB02 all you know its over 350 or under 350 but not how much.
My follow up point is that your MAF curve will most likely already be correct. Thus needing a wideband o2 sensor to tune the upper portion of your MAF curve is not necessary. I changed virtually everything in my car and the MAF curve was still correct.
A few other points. VE is not used above 3600 RPM. Above this RPM the MAF is solely used.
Tuning the non WOT/PE portions of the VE and MAF with a wideband does not make a ton of sense. Why? Because these areas of the VE and MAF will always be controlled/updated by the narrowband sensors anyways (dsteck pointed this out and he is correct). You can tune these areas all you want with your wideband and the ECM will overide whatever values you entered based on what the narrowbands say. Thus, you might as well tune the non WOT/PE areas with the narrowbands and just use the wideband to doublecheck everything.
Once again, a wideband o2 sensor is the only tool you can use to confirm your WOT/PE AFR is correct, but the chances of the commanded WOT/PE not being correct is quite slim as long as the MAF is correctly working.
Last edited by MrDrezzUp; 06-13-2009 at 09:33 PM.
06-13-2009, 09:33 PM
#25
So you are saying that I can just simply swap (both) of my stock narrowband o2 sensors for widebands? I am not using this for tuning purposes but I would like to know if I can substitute them? I have heard that they are less supseptable to fouling? Also, I already have a wideband gauge hooked up and mounted in the car.
Narrow band sensors are cheap, wideband sensors are expensive.
Wideband sensors have a short lifespan (~30,000 miles).
The ECM is expecting narrowband signals and the ECM's uses narrowband signals to control fueling. Replacing wideband for narrowband would not be good. :-)
07-05-2009, 05:50 PM
#26
ISIS SUCKS FAT CHOAD
so there is not need to say run 2 wideband controllers on a V-8? How accurate is the actual reading then if your only taking it from one side of the engine?
07-05-2009, 08:04 PM
#27
Regarding the one wideband vs. two widebands it is about diminishing returns. Is two widebands better than one? Yes. Is eight widebands better than two? Definitely. Is one wideband sufficient for most people? Affirmative.
