I need an education on AFR gauges

[GrandpaKevin]

Looking forward to some spring projects on the cars.
I'm trying to educate myself and get the proper tools to install an AFR gauge in my wife's Challenger.
Her car is running a rebuilt aluminum headed 440 Six Pack engine.
I did some basic tuning when I installed the engine and I am 95% happy with the way the car runs and drives but I think it might be running a little lean.
I haven't checked the spark plugs yet mainly because they are such a pain in the ass to remove but I'll get it done in the spring.

I am totally clueless about these AFR gauges but I think they would be a great way to help get the car tuned to perfection, especially with a Six Pack induction setup.
I assume wide band is the way to go?
I don't think I need a super high dollar one but I would like one that works well.... Any suggestions on what brand and type to buy?

I was thinking of installing the O2 sensor in the collector right past the header flange?
Is going with just one 02 sensor good enough?

I plan to install the AFR gauge and see how the car is currently running then make changes to the carbs and tune it if necessary.

Any info and advice would be appreciated.
Thanks.

[RUNCHARGER]

I bought an AEM wide band. You are better off welding the bung into the header collector, just in case the collector gasket leaks which will give a false reading. I ran the electrical cords into the car through drain plugs and under carpet so I didn't have to cut holes in the floor. I bought only one gauge, if you like you can make sure one side is dialed in and then move the gauge to the other side. After I was happy with the readings I pulled the gauge out so the car looked stock. I thought my Hemi was running 99% as well, by driving and checking plugs when setting the carbs up, turns out after checking afterwards with the wideband I was right. However it is nice to confirm seat of the pants and plug readings, if I was to run carbs again though I would mount the wideband in right away, that way you would have the carbs set up correctly in hours not in days.

[GrandpaKevin]

Yes I was planning on having bung(s) welded in the collectors on both sides then switching the O2 sensor side to side if needed.

I was planning on running the wiring through a plug on the firewall by the master cylinder but through the floor is a great idea too.

Thanks.

[dodj]

I bought an Innovate AFR
Same or similar to this one
https://www.summitracing.com/parts/inn-39180?seid=srese1&gclid=EAIaIQobChMIpZrJzKiM9gIVw21vBB3xTw0-EAQYAyABEgLVkvD_BwE
Been in my car a few years now.

[7212Mopar]

I am running EFI so I get the AFR from that on the PS. Before I have the EFI, I installed a standalone AFR on the DS using it to tune the carburetor and I kept that in the car. Both are Borsch O2 sensors but the standalone one failed me once. I think it failed due to excessive heat. They make an adapter with cooling fins and I am using it with the replacement sensor. So far no more problem. Both sides don't read exactly. They are mostly 0.5 off in between. I programmed about 15 in idle and about 12.8 to 12.5 under moderate load, about 4000 RPM. I need to monitor what the AFR is at 5000 RPM or more. I have not done that as I kept my eyes on the road at those speed. Car is really moving.

[GrandpaKevin]

Good info guys.

I forgot to mention I am also thinking AFR as eventually I'm probably going to go EFI so I might as well get familiar with it.

If the FITECH Six Pack setup had better reviews I would seriously consider it but I've been waiting for Holley to come out with their Tri Power setup.

For now I'm going to continue tinkering with the antique Six Pack carbs.

[Scooter]

Either way you go you will need to get the o2 sensor bung, might as well get one or two installed.

I picked up an inexpensive(relatively) AFR gauge made by Innovative Motorsports. Hooked up in less than an hour as I already had a bung installed in my TTI exhaust. Takes all the mystery out of carb tuning. Most have data logging capability, I never used it. Just watch the numbers as I drive.

Really helps if you have a bog off the line or are idling wayy to rich like I was. With the help of the gauge and some swapping of jets, springs and metering rods I was able to dial my carb in about as well as can be without getting EFI. Idles 12ish', fattens up nicely when I get on the happy pedal and runs high 13 low 14 on the highway. I doubt I'd be anywhere near this w/o the gauge.

My2c & GL!

[Brads70]

I'd never be without one since I installed mine. I have had to replace the oxygen sensor once in the 10 years I've had it. Mine is made by Autometer. I found every engine is different but mine likes 12.5-13 or so. Tried tuning it once  to 14+ ish and engine was not happy ( seat of the pants dyno) I also find different reading depending on who's fuel I use. REALLY helps having a carb with replaceable air/fuel bleeds
Good carbs are so expensive now they are pretty close to pricing themselves out of the market as FI systems are not much more.
I'm looking at this one of these for my Javelin project....

https://www.summitracing.com/parts/inn-39350
https://www.summitracing.com/parts/inn-37950

Hope that helps!

[Filthy Filbert]

I would suggest looking into a data logger.  I have an innovative LM-2. It's old but works.  It includes a wide band O2, it plugs into the OBD-2 port on new cars and can monitor everything....  Rpm mph manifold vacuum, water temp, etc.

It has analog inputs so you can monitor independent gauges or tachometers. 

The best part is that you can hit 'record' and then watch the readout later on a computer screen.  This way you can focus on driving and not staring at gauges. 

Then you can remove it and put a plug into the O2 bung and retain a factory appearance inside. 

[Scooter]

I would suggest looking into a data logger.  I have an innovative LM-2. It's old but works.  It includes a wide band O2, it plugs into the OBD-2 port on new cars and can monitor everything....  Rpm mph manifold vacuum, water temp, etc.

It has analog inputs so you can monitor independent gauges or tachometers. 

The best part is that you can hit 'record' and then watch the readout later on a computer screen.  This way you can focus on driving and not staring at gauges. 

Then you can remove it and put a plug into the O2 bung and retain a factory appearance inside.

^^^^ I did not plan to leave the gauge installed in the car. Was going to tune and remove.... then I became addicted to the dang thing like watching the mpg telemetry on the newer cars. lol.

[Filthy Filbert]

By the way.  Yes. Wideband is what you want.  It will display true air fuel ratio all the way to reading 21% O2 in ambient air.  (That's a good way to test calibration too)

Narrow band gauges are just useless flashing lights. "Lean, Stoich, Rich"

[GoodysGotaCuda]

Ideally you want something you can get some data off of and review, even if it's only AFR.

Being able to spot the split section lean/rich spike can help with directional accel pump tuning, adjusting when secondaries come in, etc.

Spartan and 14point7 make good stuff. I have an Innovate controller going to my megasquirt, it could be better.

[dodj]

@GoodysGotaCuda
Do you remember the sample rate of Innovate's Logworx?

[Mr Lee]

Idles 12ish', fattens up nicely when I get on the happy pedal and runs high 13 low 14 on the highway. I doubt I'd be anywhere near this w/o the gauge.

My2c & GL!

When you say "fattens up" you mean richer, yes?  Do different brand meters use a different numbering system or something?  Because 12 is richer than 14.  Not the other way around. The number represents 12 parts air to 1 part fuel.   14 parts air to one part fuel would be leaner. 

The one I have is from AEM and its a wide band. The O2 sensor failed on me but they did send me a new one and its been good.

And it's not like you can't tune without one but you will save hours and hours of time and a load of spark plugs if you're reading and replacing plugs the whole time.  And no guessing.  You can see how it's running throughout the rpm range, idling, part throttle, medium throttle and full throttle.  Wish I had bought mine sooner.  Such a valuable tool.


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[Scooter]

Idles 12ish', fattens up nicely when I get on the happy pedal and runs high 13 low 14 on the highway. I doubt I'd be anywhere near this w/o the gauge.

My2c & GL!

When you say "fattens up" you mean richer, yes?  Do different brand meters use a different numbering system or something?  Because 12 is richer than 14.  Not the other way around. The number represents 12 parts air to 1 part fuel.   14 parts air to one part fuel would be leaner. 

The one I have is from AEM and its a wide band. The O2 sensor failed on me but they did send me a new one and its been good.

And it's not like you can't tune without one but you will save hours and hours of time and a load of spark plugs if you're reading and replacing plugs the whole time.  And no guessing.  You can see how it's running throughout the rpm range, idling, part throttle, medium throttle and full throttle.  Wish I had bought mine sooner.  Such a valuable tool.


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Yes.. richer when I get on the happy pedal. If I go to WOT I'll see numbers between 8-10 to 1 and it leans out nicely cruising on the highway high 13 to low 14.