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Do you run a air/fuel ratio meter in your carbed car....

bandit67

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Guys, I am not talented in fine tuning carbs and was thinking now would be the time to weld in a bung on my 73. Running the exhaust system now. Have a fresh reworked TQ installed on a 440 and hopefully firing it up soon. If you do, what brand/model do you like best. thanks...
 
I have been using an air fuel ratio gauge for years now. I bought a Summit branded gauge. Works great, although I have replaced the o2 sensor once already.

Reading spark plugs was a practice in futility for me. The A/F gauge tells you in real time what is happening all across the range of rpm and engine load. With a Holley you can see how the carb is doing at slower cruise speed when mainly on the idle and transition circuits, when on the main jets, even when the power valve opens.

I am running a Thermoquad on one of the cars right now. Slightly leaning the idle mixture screws can greatly improve fuel economy. The gauge shows you that.
 
I liked the PLX equipment..
https://www.plxdevices.com/PLX-Wideband-O2-Air-Fuel-Ratio-Sensor-Modules-Gauges-s/125.htm
I TIG welded a bung with removable plug on to drivers side pipe as directed. Where I placed the bung, it can be easily reached to temporarily install the O2 sensor without having to jack up the car. I bought and installed a lighter plug on the PLX electronic unit so it can be temporarily powered from the car. I run the wire from the O2 sensor up the outside of the car into the window where it connects to the small electronic box. The electronics has Bluetooth, so it can easily pair with the PLX app running on your cell phone.
 
After converting to EFI, I didn't need all the redundant gauges and controls.
 
I run an AEM on my blowthru turbo jet boat. Great tool. I adjust my carb for 14.7 cruising, not in boost and 10.5:1 under boost.
 
I have used the same AEM unit on my last 3 cars. I just put a plug in the exhaust bung after removing the 02 sensor when I sold the cars.
 
I run an AEM.
tuning for ethanol is a bit different. You need to run a little bit richer to compensate. I cruise in the high 13 range and at WOT. I’m usually between 11.8-13.
 
Thanks all. Several name brands have been mentioned here with a good report and I am checking them out, haven't seen any listed as trouble, do not buy, so maybe my choice will be good.
 
None for me as I still tune as I did all my life on my carbs. Ron
 
Wide band 02 AFR gauge has to be THE most best tool for home tuning and seeing just exactly what’s going on at any given time, it helped me identify a dead spot going from cruise to WOT with my thermoquad, my secondary air door spring was bad, I have innovate and love it
 
Two AEM kits that I install only when adjusting the carb, works great.
Welded the bung in at the end of both headers.
 
Guys, I am not talented in fine tuning carbs and was thinking now would be the time to weld in a bung on my 73. Running the exhaust system now. Have a fresh reworked TQ installed on a 440 and hopefully firing it up soon. If you do, what brand/model do you like best. thanks...

Yes, but be prepared to not like what you see. It's one of the most beneficial, yet frustrating tuning tools on a performance application. Just to give you an example, my 470" low-deck is currently running 11:8-12:1 AFR on the highway, which is incredibly rich, but you would never know it by driving the car (I've pulled as much of the primary jet out as I'm comfortable with, now it's onto power valve & air bleed tuning). Of course, since the car has a wideband, you're going to know this information right away, and that act of knowing, results in a few hours or days of dedicated tuning to clear that area up on the curve.

I'm even running a wideband setup on our 318 LA truck engine, which has allowed me to tune for it's current idle (14:1) / cruise (15:1) / WOT (12.5-13:1) AFRs.

IIRC, I'm running both an AEM & Innovate wideband (can't go wrong with either). Remember, to warm the engine up slightly prior to heating up the 02-sensor. I've had good luck with Amazon 02-sensors for replacements. If you want the best 02-sensor, it's going to be from NGK. I've had many failures with the Bosch 02-sensors.
 
I'm holding out on getting one of these, too cheap I guess. I rely on plug readings. I use both edelbrock and holley carbs and have a good baseline for both setups and what the engine likes, the benefit of the AFR is not really worth it. More likely answer is I probably don't know what I'm missing but as long as I get reasonable gas mileage, good power and smooth operation I'm good. good luck with that thermoquad, it may just run well right off the bat with some light tuning if its been worked.
 
Innovate DLG-1 dual wideband for my 6bbl, and it's the best tool for ANY multi carb engine. A MUST in my opinion!
 
I'm holding out on getting one of these, too cheap I guess. I rely on plug readings. I use both edelbrock and holley carbs and have a good baseline for both setups and what the engine likes, the benefit of the AFR is not really worth it. More likely answer is I probably don't know what I'm missing but as long as I get reasonable gas mileage, good power and smooth operation I'm good. good luck with that thermoquad, it may just run well right off the bat with some light tuning if its been worked.

My 470" ran great cruising at 11.8-12:1 and achieved reasonable economy while doing it, which most owners would never realize unless they killed the ignition and coasted off the highway to read plugs. Initially, the Holley Ultra XP was so fat OOTB, it was running 10.5:1 AFR while at cruise (again, average owner wouldn't realize this) but was actually very lean at WOT and had another lean-spike during the initial tip-in. That 12:1 AFR at cruise, was the best I could achieve with what (most) owners would do, by making simple jet changes.

Squirter, pump-cam, jets, power valve, and air-bleed tuning were required to get an acceptable tune. There is no easy way to tune these 'race oriented' carburetors without a Wideband on a street car. Potential engine damage vs. $150 Wideband, easy choice with this application.

I agree however, that with most street applications, the carburetors are tuned very close OOTB. My 600 Holley (4160) on our SBM required a small jet change in the primaries and a lighter vacuum secondary spring, that's it. 14:1 AFR Idle / 15:1 AFR Cruise / 12:1 AFR WOT.
 
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I run a PLX.
The unusual thing is, when I get up in the high 13's cruising. the engine wants to surge. It seems to run happiest in the low 13s, high 12s.
My plugs look fine, so that's where it stays.
 
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