Maf lbs/min

[91Bird305]

In EFILive, they have a commanded AFR field and a MAF lbs/min. Which would show a more accurate air fuel ratio to tell if someone is running rich or lean? Here is the table. I really don't know much about MAF lbs/min compared to how rich or lean someone is running but would like to learn.

http://lknopf.servehttp.com/yellow ta.csv

 

[TurboDave]

In EFILive, they have a commanded AFR field and a MAF lbs/min. Which would show a more accurate air fuel ratio to tell if someone is running rich or lean? Here is the table. I really don't know much about MAF lbs/min compared to how rich or lean someone is running but would like to learn.

http://lknopf.servehttp.com/yellow ta.csv

There is also a column for MAF gps which we're more used to seeing and relating to. I haven't had time to look the file over real close since it's so huge! but looks like some interesting stuff.
There's a column for MAP as measured in/HG which never goes negative (never reads as a vacuum even during idle) so I'm not so sure why that is.

 

[TurboDave]

I wonder what they had it hooked up to in order to collect SO MANY data points???

 

[JDEstill]

I think that columns G and H might be O2 sensor output, and that might tell you if it's rich or lean, but if the car has a narrow band, switching type O2 sensor you can't really nail down what the a/f ratio is. The gm/s or lb/min air flow doesn't really tell you anything about it being rich or lean, nor does the commanded a/f ratio. Those are inputs, and you really need to see an output (ie O2 sensor) to tell what's really going on.

The inches Hg vacuum reading, they've got it spitting out values in the conventional way: WOT = 0.5 inHg, let off get 27+ inHg, idle at 18-19 inHg. It's just the flip side of the MAP reading, where Atm pressure = 0 and full vacuum = 29.9 inHg.

John