LC-1 vs. Stock O2 readings..
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LC-1 vs. Stock O2 readings..
Hey all,
In some recent data logs,
The lambda values aren't correlating to the AFR values.. This is on E85..
I have been tuning off my LC-1, not the stock O2.. Am I looking at this right?
My AFR's off the LC-1 are 11.76 - 11.65
The Stock O2 is reading 0.89792...
Which one is right?
My understanding is 0.89792 is 13.199 AFR....
In some recent data logs,
The lambda values aren't correlating to the AFR values.. This is on E85..
I have been tuning off my LC-1, not the stock O2.. Am I looking at this right?
My AFR's off the LC-1 are 11.76 - 11.65
The Stock O2 is reading 0.89792...
Which one is right?
My understanding is 0.89792 is 13.199 AFR....
Last edited by tkklemann; May 14, 2008 at 07:20 PM.
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From: Charleston, SC
I am knocking like crazy with only 27psi and the car is trying to run 0* at 3500 rpm.. FWIW, the Load is 300..
Knock counts wer 9, and the timing was -4* from the ECU pulling timing.. The pull made my octane level 96.86.. Argh..
I was doing better with 93 than this, which is why I am wondering if my wideband is off....
I am thinking of recalibrating, even though I did this recently, and changing the LC-1 calibration to Ethanol..
I don't have Winzip on this watered down logging/flashing laptop, so I will post the actual log tomorrow...
So far, I'm not really seeing the real benefits of E85...
Knock counts wer 9, and the timing was -4* from the ECU pulling timing.. The pull made my octane level 96.86.. Argh..
I was doing better with 93 than this, which is why I am wondering if my wideband is off....
I am thinking of recalibrating, even though I did this recently, and changing the LC-1 calibration to Ethanol..
I don't have Winzip on this watered down logging/flashing laptop, so I will post the actual log tomorrow...
So far, I'm not really seeing the real benefits of E85...
I would leave the WB on gasoline mode since thats what everyone here uses. Need a log to really help any.. FWIW I run 1* of timing at 3500rpm with E85 on the stock turbo at 28psi, and I ran 0* for a long time before that
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Narrowband Sensors can only operate at Stoich. It's Voltage jump around this stoich point from 1Volt to 0V (ideal). So the only think you know is: A Voltage near 1V means richer than 14.7 (or better: richer than lambda 1) and a Voltage nearer 0V means leaner than 14.7.
Thats why we all buy the wideband lambda Sensors.
Thats why we all buy the wideband lambda Sensors.
Complete list of mods?
I have to wonder if its phantom knock too like a downpipe banging around or something. You could always turn the boost way down to figure that one out though.
Edit:
After reviewing the log the thing that is the most interesting to me is after he stops the pull the TPS immediately snaps close but the AFR remains around the same even though the injector pulse width drops to near zero. I would think that would push the AFR to 21 very quickly but it appears to not do anything..
Could that mean what we are seeing is a missfire?
I have to wonder if its phantom knock too like a downpipe banging around or something. You could always turn the boost way down to figure that one out though.
Edit:
After reviewing the log the thing that is the most interesting to me is after he stops the pull the TPS immediately snaps close but the AFR remains around the same even though the injector pulse width drops to near zero. I would think that would push the AFR to 21 very quickly but it appears to not do anything..
Could that mean what we are seeing is a missfire?
Last edited by RoadSpike; May 15, 2008 at 10:05 AM.
You'll be much more successful tuning in lambda on your wideband instead of an AFR which is lying to you because you have it set for gasoline and your actually running 85% ethanol and 15% gasoline. Also you can run MUCH richer on ethanol based fuels than gasolene and still make power. Ethanol IS a coolant whereas gasoline is a poor coolant. FYI high 11's is probably too lean on good E85.
I agree lamba would be more of an effective tuning tool for getting the AFR right.
Here's a chart i pulled from the web.
Here's a chart i pulled from the web.
Code:
Fuel AFRst FARst Equivalence Lambda ---- ----- ----- Ratio ----- =======================--==================================== Gasoline stoich 14.7 0.068 1 1 Gasoline Max power rich 12.5 0.08 1.176 0.8503 Gasoline Max power lean 13.23 0.0755 1.111 0.900 =======================--==================================== E85 stoich 9.765 0.01235 1 1 E85 Max power rich 6.975 0.1434 1.40 0.7143 E85 Max power lean 8.4687 0.118 1.153 0.8673 =======================--==================================== E100 stoich 9.0 0.111 1 1 E100 Max power rich 6.429 0.155 1.4 0.714 E100 Max power lean 7.8 0.128 1.15 0.870 =======================--====================================
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That's where the "problem" (If it is a problem) I am seeing is, that the wideband is showing high 11's but the lambda radings out of my primary O2 are reading like the car is in the low 13's. I am not sure which one to believe..
I think I am going to change the LC-1 calibration to Ethanol, and see if it better correlates. I am wondering if my primary O2 is on its way out.
That's where the "problem" (If it is a problem) I am seeing is, that the wideband is showing high 11's but the lambda radings out of my primary O2 are reading like the car is in the low 13's. I am not sure which one to believe..
I think I am going to change the LC-1 calibration to Ethanol, and see if it better correlates. I am wondering if my primary O2 is on its way out.
I think I am going to change the LC-1 calibration to Ethanol, and see if it better correlates. I am wondering if my primary O2 is on its way out.
There shouldn't be ANY question that you should even remotely trust the front O2 sensor over a wideband for tuning ever.
Also, don't forget that a "lambda" narrowband sensor reads the lambda for the fuel being used. When you use gas, the front O2 will switch at 14.7 but with E85 lambda is 9.7AFR. The sensor only looks for a stoich burn of whatever fuel its seeing being burned. It doesn't look for "14.7:1", just 1.0 lambda. People forget that.
Last edited by Jack_of_Trades; May 16, 2008 at 04:01 AM.
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@Jack
This is exactly what I mean in my post earlier, but you find the right words.
The Sensor Voltage at the right and left of the stoich point is very unstable. Temperatur for example have a huge impact on this voltage and many other parameters also.
This is exactly what I mean in my post earlier, but you find the right words.
The Sensor Voltage at the right and left of the stoich point is very unstable. Temperatur for example have a huge impact on this voltage and many other parameters also.