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I have been doing some tuning for several years and attended thetuningschool.com. There method of tuning basically consists of using STFT's to calibrate the VE and MAF. While this seems to work great in most cases, I have also been looking into Greg Banishes tuning teachings. As far as I can tell so far, he uses the wideband to correct VE and MAF. In the beginning of his dvd he goes over how lambda works and how much easier it makes things for tuning part throttle. In that part he uses a gauge that costs more than $3k. While I'm sure some shops use those, I don't know of any. I would however like to look into the lambda reading more. Do most here agree or do you think I should stay with AFR and figure out the difference. I only tune gen 3 PCM's and don't use ethanol or other fuels. If Lambda is that much better, what is a good WB to use that easily goes from car to car like my LM2?
You first have to realize that an o2 wideband sensor measures one thing: o2 content. Not hydrocarbons.
With that in mind, using lambda enables you to use the same scale and ratios for ANY hydrocarbon.
1 lambda in gas, ethanol, methanol, propane, diesel, is all the exact same thing. How is thag possible? Well because the sensor READS oxygen content not "fuel" content.
The gauge or wideband you bought is just programmed to spit out an AFR reading through a simple formula.
1 lambda in gasoline afr scale would be approx 14.68 afr, while using pure ethanol, it would be approximately 9 afr.
There is a huge discrepancy between 14.68 afr and 9 afr..especially when you start using methanol..you dip in the low single digits.
In order to prevent memorizing all these afr numbers, lambda enables us to "normalize" or set a standard for fuel ratios.
1 lambda in gasoline will be 1 lambda in ethanol etc etc
Studies show that generally max mbt is reached with a lambda valur of .89 so what does that mean? Well assume you are using gas AFR. Stoich is 14.68, multiply that by .89, and you get the air fuel ratio that you should command whenever you want to make the best power which is about 13 afr. Now if lets say we were using 100% ethanol, the stoich is 9 afr, multiply times .89, you should be commanding about 8 afr. we get different numbers using afr scale, but we use the same lambda value of .89 for n/a fueling.
Rule of thumb in lambda
1=stoich
.89= lambda value for n/a (rule of thumb)
.78= forced induction
Throw that LM wideband to the trash, innovate is garbage. Use an NGK AFX with an ntk wideband sensor. Much more accurate and the closest youll have to the lambda pro that banish uses.
If youre going to tune solely gasoline then lambda wont really benefit you to know, but it starts becoming useful when you start mixing fuels such as meth injection with 93.
After reading the output channel set up for the LM2 I guess I kind of figured out that it doesn't change out put V. Lambda 1 and 14.7 afr are the same. I guess I would just need to set up the scanner to read it as lambda.
As far as a different WB goes, AEM claims to have the fastest and most accurate with its new X series. Any thoughts on that?
I have also done the tuning school course. As I remember it they used the long term fuel trims, as opposed to the stft's. I wonder if they changed their methods? I'm confident it was LTFT used when I did it. Honestly I was disappointed when I seen that this is how they did it. I don't really agree it being a very good method. It is fine with a close to stock setup, but tuning 3 Bar SD cars making over 1000 whp it is only applicable to the cruising area. It is really hard to get enough data to get fuel trims established for much of the VE table outside of the normal cruising range. For these areas I have to look at my wide band data and estimate what the VE table should be in these less used regions, then blend or smooth it into the area I have good LTFT data for. To be honest I did learn a little from the course, mainly in the area of idle tuning, but I expected more from it. I probably would need to take the advanced course to get much out of it, but I'm reluctant to spend the money, since the first course didn't add much to my skills.
I always work in Lambda, but it makes no difference. AFR is just Lambda multiplied by stoich for the fuel you are using. It is just semantics in my opinion. I don't have a dyno, but a local guy has one I can rent by the hour to tune on. He tunes as one of the services he provides, but I don't do it professionally. I tune my own vehicles, and for friends and relatives. Occasionally for a friend of a friend, just as a favor. I usually run double widebands if I can, one I can route into HPTuners, and the one that is a fixture of the dyno. The dyno has additional tools on it like a map sensor you can attach to a vacuum line to log boost, a pick up to put on a coil pack to log rpm, and a wide band to go in the tailpipe. It is actually measuring Lambda but it's output is in AFR. To get Lambda from it I just divide it by 14.7. I like having 2 wide bands, that way I have one verifying what the other is reading correctly. If I have 2 wide bands telling my I'm at 0.77 Lambda on E85 at high levels of boost I get a confidence I'm where I want to be. I do use an innovate of my own and always have very good correlation with the one that is part of the dyno. I too have heard negative feedback on the Innovate products, so I have always been suspect of it. However I'm starting to think that it is either inconsistency from unit to unit, or it is sensitive to setup. I've had great results with mine, and have been using it for about 4-5 years. The only time I've had problems is if the bung for the sensor is too close to the outlet of the turbo. I like them at least 18" after the turbo, preferably 24" or more.
The real advantage of using Lambda is when you start creating fuel cocktails. Gas + 10% ethanol. E10 Gas + methanol injection. Gas + 50% ethanol. E85 + methanol injection. Or in my case: Gas + E30 + propane injection - it would be a guess to try and determine the stoich value and target AFR for that - lambda just works. Adjusting the PE and boost enrichment tables (timing adjust to suit) makes it so much easier.
After watching Greg's DVD, (I've had it a while but just now really watched it and paid attention) that pro lambda sensor seems to work quite well. All of the sensors I have dealt with seem to jump around so quickly I can't wrap my head around where they even begin to average. After watching the VE and MAF tuning sections I realize that when you are looking at averages in each cell it becomes much clearer. Also after seeing how close things were after just one round of corrections, it sure seems much more efficient than using fuel trim error.
Lambda, AFR, and EQ Ratio are just scales. Lambda and EQ are the same only the inverse of one another. 1/Lambda = EQ and 1/EQ = Lambda. You can tune in any of them if your logging the correct parameters and using the correct data for stoichiometric. Most of your wideband if not all of them use lambda and convert to AFR for your gauge to display.
The advantage of lambda is stoch is 1.00 for any fuel and you use the same scale for all fuels. If your not used to lambda you can always setup your scanner to log in AFR and Lambda and see how they correlate. If your on pump gas its not a big deal, tuning a flex fuel vehicle with e85 or any mixture of ethanol you see quickly why tuning in lambda is easier when mapping out commanded afr vs actual and commanded lambda vs actual.
In HPT v3, it defaults to Lambda. So it makes it a shitload easier.
So are all of the widebands now, going to log in lambda on HPT? I have the NGK and haven't swapped over to lambda, because my gauge doesn't, and I don't want to be going back and forth between afr to lambda and back. There is too much more room for error.
I still have last summers version on HPT. I think it's 3.2, and it still logs AFR. I haven't touched 3.4 yet.
Hi Cody, good question AND PREFECT "tech" by Subeone.
I too have a Horiba UEGO Meter used to calibrate my ECU-882 "look-up" tables.
YES again, I tune with Lambda @ .891-.903 as common with .781-.863 for SC engines in most cases.
My ECU-882 can specify the AFR number requested in the "units" table.
WE do many AFR's such as Meth, E-100, E-85, NG, Propane, etc.
MY CONCERN is for Cody's LM-2 as the Innovate method is to "toss" the UEGO Calibration Resistor.
I Invented the Four Wire EGO for NTK using my bench dyno, and TWO sensors in the same pipe at the same time. (one EGO three wire AND one UEGO semsor)
I added a ground wire to the body of the EGO (three wire now four wire) with the "read" better than the UEGO, much faster.
My method was to ADD a scope leed to the 0-1 volt output with witness of EACH Cylinders firing Lambda measurement better than the UEGO. (1980's)
The LM-1 was invented later and tested with the same test, one pipe with TWO sensors.
The "read" was MUCH different when the Horiba UEGO/Innovate UEGO were reported with the LM-1/2 read as a 12.00 AND proper read of the Horiba as 13.00 AFR.
This report was provided to NTK with the "repair" method of creating their OWN BRAND AFRM.
I tested one of the first, on my bench dyno finding the AFRM/Horiba as EQUAL in the AFR report.
I fit the NTK "hot start" sensors most often AND when used in an engine with normal operating conditions, they work VERY well with a cost of $ 65.00.
Lance
Last edited by pantera_efi; 10-07-2017 at 11:08 AM.
Lambda, AFR, and EQ Ratio are just scales. Lambda and EQ are the same only the inverse of one another. 1/Lambda = EQ and 1/EQ = Lambda. You can tune in any of them if your logging the correct parameters and using the correct data for stoichiometric.
Agreed.
With my two personal widebands they read stoich but output AFR, and they make stoich a 14.7 reading on the display. Guess what, I set my PCM to 14.7 stoich, command 14.7 stoich, make corrections and IM DONE. I have no clue why on a 411 PCM why you would start jacking around trying to reinvent the wheel. The "math" forms you a VE table with a percentage correction using AFR error with is the same as lambda error or eq ratio. So retarded to make it more complicated. My .02.
How so? My wideband outputs 14.7 for stoich. It doesnt matter what fuel you're using, if its stoich, its 14.7 on the display. Tuning to 14.7 on the display is tuning to stoich. You guys crack me up.
Nope crybaby, Im asking you to explain how eq ratio makes "tuning for different fuels" easier. I agree when setup properly all accurate data can be used to correct fueling. But why undo something thats already programmed to work correctly? If you can make a logical explanation Id be willing to listen. Wanna know what Ive seen? It confuses the **** out of people. You EQ ratio people need to get off your high horse and make things as simple as possible for the newbie tuners.
02-21-2017, 11:43 PM
Can we discuss lambda vs afr? 
While I'm sure some shops use those, I don't know of any. I would however like to look into the lambda reading more. Do most here agree or do you think I should stay with AFR and figure out the difference. I only tune gen 3 PCM's and don't use ethanol or other fuels. If Lambda is that much better, what is a good WB to use that easily goes from car to car like my LM2? 
