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A/F ratio

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Old 02-23-2011 | 07:47 AM
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Default A/F ratio

Is there a way to calibrate the A/F ratio without having the engine on a dyno? If so how do I do it and what do I need?
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Old 02-23-2011 | 07:56 AM
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Sure, what exhaust do you have? Have a bung in welded in your exhaust and use a wideband O2 sensor to monitor. You could use a gage or a handheld monitor. There are a bunch of kits out there.
I have a Holley MPI kit and I can adjust mine with the laptop.
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Old 02-23-2011 | 08:30 AM
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I'm running K/E headers, I'm going to have the tails modified so I'll have them add a bung in the tail pipe.
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Old 02-23-2011 | 08:30 AM
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Do you have EFI or carb? You can install a wideband O2 as jeffswav said to measure the A/F ratio. Here is where you can get one at. http://www.innovatemotorsports.com/products/lm2.php
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Old 02-23-2011 | 08:34 AM
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I'm running a carb.
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Old 02-23-2011 | 08:37 AM
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Originally Posted by endeavour32
I'm running K/E headers, I'm going to have the tails modified so I'll have them add a bung in the tail pipe.
Just be sure they will not get wet...
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Old 02-23-2011 | 09:25 AM
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Originally Posted by 28Eliminator
Do you have EFI or carb? You can install a wideband O2 as jeffswav said to measure the A/F ratio. Here is where you can get one at. http://www.innovatemotorsports.com/products/lm2.php
Not to hijack the thread but I am also looking to monitor A/F ratio and the product shown looks interesting. Can you just "monitor" the A/F ratio or can you change it? I have an adjustable fuel regulator so I know I can change fuel pressure but if I do not have the correct A/F ratio do I need to have my ECM re-programed...??? (Running a Procharger @ 5lbs on a 454 Mag MPI))
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Old 02-23-2011 | 09:35 AM
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Originally Posted by FogduckerIII
Not to hijack the thread but I am also looking to monitor A/F ratio and the product shown looks interesting. Can you just "monitor" the A/F ratio or can you change it? I have an adjustable fuel regulator so I know I can change fuel pressure but if I do not have the correct A/F ratio do I need to have my ECM re-programed...??? (Running a Procharger @ 5lbs on a 454 Mag MPI))
You can check it with the monitor, if it is off have one of the guys here reprogram it for you.
Mine is cool because I can do it myself and I can set target A/F ratios and let the PCM tweak it out.
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Old 02-23-2011 | 09:38 AM
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Originally Posted by FogduckerIII
Not to hijack the thread but I am also looking to monitor A/F ratio and the product shown looks interesting. Can you just "monitor" the A/F ratio or can you change it? I have an adjustable fuel regulator so I know I can change fuel pressure but if I do not have the correct A/F ratio do I need to have my ECM re-programed...??? (Running a Procharger @ 5lbs on a 454 Mag MPI))
You can use you fuel press to offset the fuel curve but it won't change the shape of it.

Jeff
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Old 02-23-2011 | 09:48 AM
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Just trying to wrap my head around this......so if I find I have the A/F ratio a little "lean" at say 12 or 13, I can find this out with this kit but would have to send the ECM in to be re-programed? Or at those numbers, (I was told about 11.5 is what I should be running) can I richen it up a little with higher fuel pressure???

Jeffswav, what do you mean by letting the PCM "tweak" it out..? Thanks.
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