This topic came up in the chat as well as I have seen some posts about AFRs (lean/rich conditions) so I thought its a good time to hash this out. First here is a graph comparison between WBo2 and a typical NBo2.
Now before I go too far past this I should mention that this is a representation of what your NBo2 is doing. The actual voltage values may vary slighty against this graph. The shape of the curve is right on though and will illustrate the flaw of trying to use a NBo2 for high performance tuning.
(Black dotted line) As you can see the slope of the curve is very steep except for one place and only spans 1V. Right around stoichmetric. This is to satisfy what car manufacturers are looking for ... fuel economy. But this comes at a price of absolute shitty resolution anywhere else in the AFR range. .05V represents 1 AFR in most places! Since most of us with a turbo will tune for somewhere between 12.5:1 to 11.5:1 this blows huge donkey balls.
Enter WBo2 sensor. (Black solid line) As can tell from this graph it maintains a constant slope. NOT ALL WBo2 graphs look like this. Some do have varying slopes but they are all relatively flat. This particular WBo2 Controller is the AEM Gauge Type UEGO Controller. AEM makes a non gauge type UEGO that is made to go with their EMS. That unit's AFR voltage graph is NOT the same as this one. Don't ask me why but we'll discuss that a little later.
Anyways, it's a fairly constant slope that ranges 5V (yes I know it only goes to 3.5V but you're already stupidly lean and blown up your motor at that point so who cares what the AFR is at that point). Makes it easier to find out what AFR you're at.
I think this graph will help people understand why your blinky 0-1V AFR gauge is pretty worthless and why when your NBo2 gauge says your rich it really doesn't mean much. There is just not enough resolution to see where you really are.
I'll probably add more to this when I get home tonight but this is enough for Part 1. Part 2 ... Wideband controllers ... how can they use the same freaking sensor and not be compatible with one another?!
#84423, "RE: NBo2 WBo2 Comparison / AFR Discussion" In response to Reply # 0
Good stuff, Thura. I still think a narrow band gauge is still a lot better than nothing, because it tells you when you are richer or leaner than 14.7:1, which can at least put you in one ballpark or another.
#84430, "RE: NBo2 WBo2 Comparison / AFR Discussion" In response to Reply # 1
Originally posted by ner947 Good stuff, Thura. I still think a narrow band gauge is still a lot better than nothing, because it tells you when you are richer or leaner than 14.7:1, which can at least put you in one ballpark or another.
Thats about all it does. But I agree it's Better than nothing.....
I eat emo kids for breakfast
1995 Eagle Talon (SOLD) 72' SuperBeetle 72' Standard Beetle 56' Deluxe Beetle
#84480, "RE: NBo2 WBo2 Comparison / AFR Discussion" In response to Reply # 3 Mar-31-05 05:05 AM by turbo8u
Originally posted by xcasbonx Why can't a company make an AF/R gauge that can read from 0-5v for accurate readings?
they do, but they read wideband sensors not narrowbands
this thread rocks
just a quick question, do you guys see wideband's being used as OEM equipment to replace standard narrowbands on future cars? i remember back in the day, some hondas had widebands stock but i think that was for emissions and such.
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96 Black ESi 91 Red TSI AWD (RIP) 02 WRX
"turnin wrenches for nine hours in the pouring rain, just to get the beast up and running again"
Aerospace Certified TIG welder for Precision Castparts in Portland, OR.
#84481, "RE: NBo2 WBo2 Comparison / AFR Discussion" In response to Reply # 4
Originally posted by turbo8u
Originally posted by xcasbonx Why can't a company make an AF/R gauge that can read from 0-5v for accurate readings?
they do, but they read wideband sensors not narrowbands this thread rocks just a quick question, do you guys see wideband's being used as OEM equipment to replace standard narrowbands on future cars? i remember back in the day, some hondas had widebands stock but i think that was for emissions and such.
There is a few reasons why companies don't make AF/R gauges that read 0-5V. Almost no car comes with WBo2 sensor from the factory. Somehow, someway each controllers/sensors voltage outputs vary just enough from manufacturer to not be interchangeable (I'll illustrate this a little later if I ever get a chance to write part 2). Lastly, it is a little more involved electronically to control the WBo2 in comparison to the NBo2.
I doubt OEM equipment will ever carry WBo2. It's more expensive for them to engineer something to control the WBo2 (more in terms of mass manufacturing) and they just don't need that fine a resolution to make the cars on the street. They put a fuel/spark map in the car that is fine tuned for the stock setup. The car doesn't come from the factory in a tuneable condition so there wouldn't be much of a need for it.
#84485, "RE: NBo2 WBo2 Comparison / AFR Discussion" In response to Reply # 5
Originally posted by Avenger They put a fuel/spark map in the car that is fine tuned for the stock setup. The car doesn't come from the factory in a tuneable condition so there wouldn't be much of a need for it.
i wouldnt say it was really fine tuned, i think its fair to say its more of a base tune. when i had my wideband on my friends STi for example it was considerably rich on the stock fuel maps, but i think that subaru just did that to be on the safe side. same thing with our 2gnt's, they were tuned quite rich. i agree with you though that from the factory they dont need to be tuned and dont have much of a need for it. if the stock ecu on a boosted STi read a wideband though, for example...that bitch would feel SO NICE, even at low throttle. the ecu would have much more to work with, but like you said...it doesnt really need it from the factory.
whats the ADVANTAGES of a narrow band? besides 'cost effectiveness'...?
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96 Black ESi 91 Red TSI AWD (RIP) 02 WRX
"turnin wrenches for nine hours in the pouring rain, just to get the beast up and running again"
Aerospace Certified TIG welder for Precision Castparts in Portland, OR.
#84488, "RE: NBo2 WBo2 Comparison / AFR Discussion" In response to Reply # 4
Originally posted by turbo8u
Originally posted by xcasbonx Why can't a company make an AF/R gauge that can read from 0-5v for accurate readings?
they do, but they read wideband sensors not narrowbands this thread rocks just a quick question, do you guys see wideband's being used as OEM equipment to replace standard narrowbands on future cars? i remember back in the day, some hondas had widebands stock but i think that was for emissions and such.
Volkswagons use a Bosch wideband on all their cars and their turbo models have build in wideband in the ecu.
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But I agree it's Better than nothing.....
