Air fuel ratio meter questions

6

69stang_250

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Any of you have a preference on a brand of A/F gauges or meters?
I am thinking about getting a gauge and having it installed long enough to tune the carb and then pull it out.
Is there anyone that makes a meter you can rent or use as a tool vs a constant fixture in the vehical?
Thanks for any help guys.
 
69stang_250":2u1ifbb5 said:
Any of you have a preference on a brand of A/F gauges or meters?
I am thinking about getting a gauge and having it installed long enough to tune the carb and then pull it out.
Is there anyone that makes a meter you can rent or use as a tool vs a constant fixture in the vehical?
Thanks for any help guys.
Click to expand...

I have an AEM Wideband and am happy with it, and you will need an 18mm bung welded into your exhaust (a nut welded on works, and it can be plugged with a bolt if you remove the o2 sensor).

You really do need a Wideband sensor/guage, the much cheaper narrowband ones are useless for tuning.

If you don't need it for long, you could borrow mine...
 
"if you don't need it for long, you could borrow mine..."
WoW, nother ford6 service!
:D
That reduces costs by $150 (not sure on the meter.)
Rich: What do you recommend on 1 of those?

I C a Bosch wb O2 for $160...
Meters twice that cost?
 
Rich I may take you up on that offer.
I just don't really want to mount one in the car.
I will be going to EFI at some point and was planning on getting a bung welded in anyway.
I'll shoot you a message when I get back to CA next week.
 
Well I went in and ordered one myself.
I got to thinking and I will be needing it for tunning down the road as well.
Is the wiring pretty straightforward? I'm just want to set it up where I can plug it in and tune, then take it out once done. Any advise on what A/F ratio I should shoot for? I've heard and read between 14.7-12.5. Does that sound right? I know there will be fluctuations in this number based on driving conditions. Should my A/F ratio stay between those numbers in all driving conditions and throttle positions?
 
You average the readings the AFR gauge displays as your driving conditions and carb tuning varies. The AFR readings constantly fluctuate but the average of readings at idle, cruise and WOT are the needed info for carb tuning. The LED arc behind ratio display numbers are easy to decipher while trying to look and drive. Most AFR gauges can output to a computer for logging and later analysis. The bung is welded or can be clamped on exhaust and typical underdash gauge setup with switched power from batty and umbilical to sensor... . My newer Auto-Meter AFR waits until batty' is over 12V with alternator charging and counts down from 20 sec's while heating the Bosch exh. sensor before displaying..


I set up a Holley 2300 2Bbl according to typical mods for Blow-Through forced induction. It ran good on static engine testing with no load. Under driving conditions it ran terrible so I tweaked carb jets and PV richer. I finally got a AFR gauge and immediately showed pig-rich AFR's at cruise and WOT. With some jetting and PVCR channel tweaking the AFR's now are @ 14-15 at idle and cruise and rise to @ 10-12 at WOT. An AFR gauge is another important tool for actually driving a project.

have fun

 
Seriously! I am always amazed at how a car that feels right can show such poor AFR or EGT - then you dial the numbers in and it's even better. You can only do so much with your ear and your butt!
 
69stang_250":2rx8siw5 said:
Well I went in and ordered one myself.
I got to thinking and I will be needing it for tunning down the road as well.
Is the wiring pretty straightforward? I'm just want to set it up where I can plug it in and tune, then take it out once done. Any advise on what A/F ratio I should shoot for? I've heard and read between 14.7-12.5. Does that sound right? I know there will be fluctuations in this number based on driving conditions. Should my A/F ratio stay between those numbers in all driving conditions and throttle positions?
Click to expand...

You want to be a bit rich at WOT (12-13 is likely enough for N/A) and can be fairly lean at idle (15 or more even), cruise you likely want around stoich (14.7)
 
That was the info I was wondering about.
Does it matter the angle you install the o2 if it is not permanently installed?
 
69stang_250":3cgikoli said:
That was the info I was wondering about.
Does it matter the angle you install the o2 if it is not permanently installed?
Click to expand...
I would still have the wire pointing upish of level, just to be safe...
 
I was thinking about installing it straight up due to how the header pipes sit when installed.
They are very close to eachother and installing it inside the engine bay near the starter is about the best place I can think of, right behind the bend of the 4-5-6 collector head pipe.
 
69stang_250":1kgbrtwa said:
I was thinking about installing it straight up due to how the header pipes sit when installed.
They are very close to eachother and installing it inside the engine bay near the starter is about the best place I can think of, right behind the bend of the 4-5-6 collector head pipe.
Click to expand...

hmmm, I would really think about putting it directly in the x-pipe myself, so it reads all cylinders...
 
What about a bung in each collector, easier to find out who is who and tune front group and then back group move back and forth..Once each is tuned, leave it in leanest ..Maybe two sensors with a selector switch.
 
AFR installation spec install close to manifold or at output of header-collector. Also for Dual-Out headers install' said use of one sensor after one of the collectors is fine. .

Two sensors switched to average would be best but most complicated, two bungs could easily have the sensor switched for tuning. ....

have fun










 
So I was being a little lazy and got one of the bung band clamps. Was pretty easy to install and I don't think it will leak as tight a fit it is with the seal under.
I thought about two o2s, but that was a little more than I wanted to do as well. I have the o2 bung installed straight up and even with the bell housing. Shouldn't be too much of a pain to remove and install the o2. And I got an oil pan plug to cover the bung when not in use.
 
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