AFR readings

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I generally tune WOT for best power....... and the A/F ratio is what it is.

I can’t think of any Mopar engine I’ve ever tested that made the best power with the A/F ratio so lean it would hurt itself.

If you’re new to using an A/F ratio gauge....... it’s probably a good idea to familiarize yourself with Lambda, and what the gauge is actually telling you, with regards to different fuels.
 
That ^^^^^ is really what your shooting for.
Nevermind what is and is not perfect according to the world at large.

But here is a question….. are you able to run at a track to know what works best?
 
Car is a drag car only. For years I used to mix Sunoco 110 with 93 pump gas as I had issues on really hot days with the fuel boiling in the carb and creating a stumble when I tried to run just 93. I have since switch my fuel system from a dead head to a by pass system to help keep the fuel cooler and have went back to straight 93. When I was mixing fuel I was doing 2 gal 110 to 3 gal 93 and my AFR reading was 12.7 at WOT. Now with straight 93 it is 13.3. The car does have a snorkel style hood scoop and I didn't used to run an air cleaner, but this year I installed a 9" filter and used a K&N Drag filter (Grey and can pretty much see thru it). I need to install some new plugs to get a good reading on them, but this past weekend the car which is usually pretty consistent was deadly consistent in the 5 runs I made.
 
moparstud440 said:
Car is a drag car only. For years I used to mix Sunoco 110 with 93 pump gas as I had issues on really hot days with the fuel boiling in the carb and creating a stumble when I tried to run just 93. I have since switch my fuel system from a dead head to a by pass system to help keep the fuel cooler and have went back to straight 93. When I was mixing fuel I was doing 2 gal 110 to 3 gal 93 and my AFR reading was 12.7 at WOT. Now with straight 93 it is 13.3. The car does have a snorkel style hood scoop and I didn't used to run an air cleaner, but this year I installed a 9" filter and used a K&N Drag filter (Grey and can pretty much see thru it). I need to install some new plugs to get a good reading on them, but this past weekend the car which is usually pretty consistent was deadly consistent in the 5 runs I made.
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Does your 93 have a blend of ethanol in it?
 
If your gauge is set up for “straight gas”(14.7:1 stoich), then when it’s reading “13.3:1”, that is basically .905 lambda........ which is 12.75:1 if you’re running E10 gas.

.91 lambda is on the lean end of the normal WOT tuning range for E10.
Try going a little richer and see if it likes it.
 
I bought an innovative dual 02 sensor set up.
I’m having trouble getting the dang thing to read most of the time. So far, it’s read the AFR on both sides twice out of the 6 times it even reported anything.

When it’s working, it at least points me in a direction.
 
rumblefish360 said:
I bought an innovative dual 02 sensor set up.
I’m having trouble getting the dang thing to read most of the time. So far, it’s read the AFR on both sides twice out of the 6 times it even reported anything.

When it’s working, it at least points me in a direction.
Click to expand...

Grounds and power with any interference makes them go wonky.

I direct ground mine to battery
 
crackedback said:
Grounds and power with any interference makes them go wonky.

I direct ground mine to battery
Click to expand...
Ditto, right to the battery are both wires. I go through the steps and everything is ether fine and I start the vehicle and get nothing or I get nothing. Just “HTR” that does t go off most of the time.

Time to call innovative
 
rumblefish360 said:
Ditto, right to the battery are both wires. I go through the steps and everything is ether fine and I start the vehicle and get nothing or I get nothing. Just “HTR” that does t go off most of the time.

Time to call innovative
Click to expand...

Check the connector at the sensor. Make sure all the wires/pins are engaged fully. They are have a history of not being all in, so to speak. Might have a bad sensor off the go.
 
crackedback said:
Check the connector at the sensor. Make sure all the wires/pins are engaged fully. They are have a history of not being all in, so to speak. Might have a bad sensor off the go.
Click to expand...
At least two of us have found poor connections at the power plug (used with the dash cigar lighter socket).

photos in these two posts
Proform 850 dialing it in closer
 
PRH said:
I generally tune WOT for best power....... and the A/F ratio is what it is.

I can’t think of any Mopar engine I’ve ever tested that made the best power with the A/F ratio so lean it would hurt itself.

If you’re new to using an A/F ratio gauge....... it’s probably a good idea to familiarize yourself with Lambda, and what the gauge is actually telling you, with regards to different fuels.
Click to expand...
Thats the truth
thumbs_up-gif.gif

Using lambda the fuel doesn't real matter.

IMO the main use of the logger at the dragstrip is to observe the trends.
Examples posted here where I'm looking at how flat the AFR is.
Also cudafever does the same here Proform 850 dialing it in closer

If I was changing jets I'd be looking to see if the AFR shifted as expected by the jet change.
When timing is adjusted, if there is an AFR change - generally that's not a change in Fuel to Air supplied but a change in the burn that effects the left over O2. (Think of it this way, if the AFR curve is fairly flat at WOT, then clearly a there is a pretty wide range of velocity and volumetric flow where the carb is providing the same fuel to air volume.)
 
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