How to install an APC Air/Fuel Ration Gauge

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#11

04-19-2011 | 02:37 AM

CPTAFW163

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Joined: Jun 2004

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From: Ft Campbell, KY/TN

Quote:

Originally Posted by matty675

a narrow band is completely inaccurate at anything above 14.7. this is due to the temperature variable when an engine is running rich. a voltage signal in the rich range is entirely dependent upon temperature as one voltage can indicate entirely different ratios. temperature is unmeasured with a narrowband sensor.

wideband sensors contain a current pump that determines actual o2 concentration and the level of o2 required to re-establish stoichiometric pressure AFR.

why would you need a gauge to tell you that you ARE running at the correct A/F ratio?

if you swap injectors and are running rich/lean. Then you can reprogram your PCM to trim or add fuel throughout the curve to maximize gains. Too much fuel boggs the engine, too little starves it. If you take the AF ratio at WOT and send that number to a programmer (like hemifever) you stand to gain about 15 HP and about 3 MPGs like I did.

I needed a wideband, but only because i am running Bosch 24# injectors.

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#12

04-19-2011 | 07:57 AM

HeyYou

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From: Clayton MI

For tuning purpose, you need a wideband. Narrow band are inadequate to the task.

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#13

04-19-2011 | 11:02 AM

Silver_Dodge

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From: Colorado

I like the narrow band just to tell me if I am running lean or rich under certain conditions (which is does perfectly), and how well my PCM is doing maintaining in closed loop mode.

If you want the exact lean/rich ratio, then you have to go wideband.

Each have their uses.

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