Results 1 to 17 of 17

Thread: AFR Actual in Lambda

  1. #1
    Tuner Dave_In_VA's Avatar
    Join Date
    Sep 2021
    Location
    Northern VA
    Posts
    73

    AFR Actual in Lambda

    Hi, how do I setup actual AFR reported in Lambda without using a wideband?

    My car has an E40 ECM.
    2005 Corvette, Z51, 6sp Coupe:
    - TSP ported/milled LS3 heads
    - 11:1 compression
    - Ported OEM LS3 intake & LS2 throttle body
    - 222/230 113 +3, 0 degree overlap w/1.7 rockers
    - Comp 1.8 roller rockers
    - Lift w/1.8 rockers .630/.621
    - Johnson 2110 lifters
    - OEM LS3/7 Injectors
    - LS3/7 style CAI w/blade MAF sensor
    - Std. speed ATI balancer
    - C5r timing chain
    - ARH 1 7/8 headers w/cats
    - C6 Grand Sport MPP Mufflers with NPP in a Box
    - C7 ZR1 Style wheels: 18x9.5, 19x11
    - C6 Z06 Brakes

  2. #2
    Tuning Addict 5FDP's Avatar
    Join Date
    May 2012
    Location
    Rogers, MN
    Posts
    12,844
    A wideband is required to report actual AFR number.

    GM only uses narrow band sensor in the LS engines.


    But to log AFR or Lambda, just pick that channel. Choose commanded AFR or choose EQ ratio to be logged in the scanner, those will just show what the computer is asking for but not the real values in the exhaust.
    2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.

    If you don't post your tune and logs when you have questions you aren't helping yourself.

  3. #3
    Tuner
    Join Date
    Jan 2017
    Location
    Saudi Arabia, Yanbu
    Posts
    53
    Connect your WB to your device and see your actual AFR/Lambda
    add commanded AFR/Lambda channel after that make a histogram use AFR/Lambda error to deal with your fuel
    Abdulaziz T Hadi - E-mail: A7tuner@hotmail.com

  4. #4
    Senior Tuner blindsquirrel's Avatar
    Join Date
    Apr 2017
    Location
    Meridian MS
    Posts
    4,029
    You skipped the 'buy a wideband' and 'then install it' steps.

  5. #5
    Wideband is a must! Makes you wonder why you'd ever mess with stock narrowband.
    2006 GTO 403ci lsa heads kooks long tubes corsa ss exhaust OTR intake HPTuned

    2010 GMC Sierra LMM Duramax. Exhaust and tuned

  6. #6
    Senior Tuner blindsquirrel's Avatar
    Join Date
    Apr 2017
    Location
    Meridian MS
    Posts
    4,029
    Narrowbands are actually more accurate at stoich, and that's where most engines spend most of their time, and also if the narrowbands are in control of the fueling in closed loop why would you want those parts of the map tuned with a different, completely unrelated aftermarket sensor? Yeah, narrowbands sure are dumb!

  7. #7
    Senior Tuner kingtal0n's Avatar
    Join Date
    Feb 2017
    Location
    miami
    Posts
    1,103
    Quote Originally Posted by Stroked06Goat View Post
    Wideband is a must! Makes you wonder why you'd ever mess with stock narrowband.
    Makes you wonder indeed! Ever since my first wideband in 2004 I never used another narrowband since then.

    Why be accurate at an air fuel ratio that isn't optimal for anything? No engine should spend time at 14.7:1.
    Best economy? 15 to 16's
    Best torque and power? Not 14's thats for sure.
    What is 14's good for: Nothin!

    Well, I hill climb with 65-70KPA @ 13.8 to 14.2, thats something I guess. Still, not 14.7!

    Cylinders are averaged across one sensor anyways, so even if the wideband/narrowband says 14.7, none of the cylinders are actually running 14.7, each is off slightly due to variability between them. More cylinders? More variability.

    Not to mention temperature influences the sensor. Hotter = reads richer. Slight, but, its there. I've measured it. At 1600*F cheap widebands will say 11.5 when its really 15:1. Imagine my surprise... I have a nice hour long dyno session video of an engine burping up some smoke as the piston rings lose tension due to the high temp. What an experiment that was...

  8. #8
    Senior Tuner blindsquirrel's Avatar
    Join Date
    Apr 2017
    Location
    Meridian MS
    Posts
    4,029
    Another thread I have to adblock now. Thanks.

  9. #9
    Senior Tuner kingtal0n's Avatar
    Join Date
    Feb 2017
    Location
    miami
    Posts
    1,103
    Blind do you want me to not post in threads that you post in? Because if you ask.... I won't. I don't want to upset you. I am just joking around with you man. You are an enormous asset to this forum and I appreciate you being here for these folks, you certainly can do more for them than I can regarding HPtuners. Please lighten up though, I'm just trying to have some fun and teach in the process. I teach engineering freshman and its fun for me. Your dour attitude is on the verge of despressing sometimes... I wonder if you are in pain? Are you hurting? I had an injury once for a looong time and it made me like that, always kind of sour. In any case I mean no disrespect. If anything I respect you more than anyone else because I know better about your ability and more aware of what you are capable of than most people who read and post. <3 Love you and I would give you anything to help you

  10. #10
    Senior Tuner blindsquirrel's Avatar
    Join Date
    Apr 2017
    Location
    Meridian MS
    Posts
    4,029
    If you know of a way to use a wideband as the primary closed loop fuel control on a GM ECM/PCM, then post it up so we can all move into the 21st Century. Otherwise drop the narrowbands-are-evil preaching, you sound like everybody's crazy uncle talking about fluoride in the water and the Catholics.

    You are doing your openloop4lyfe thang, you like it, that's fucking great dude, you do you. Stop the preaching.

  11. #11
    Senior Tuner kingtal0n's Avatar
    Join Date
    Feb 2017
    Location
    miami
    Posts
    1,103
    heres an example arduino project of a wideband simulate narrowband output
    https://thedeltaecho.wordpress.com/2...p-afr-control/

    In this one they used the LC-1 directly
    https://forum.hptuners.com/showthrea...ow-Band-How-To

    Do I get a cookie?


    I don't know why you don't prefer open loop. Have you tried it? And What is making you sound so angry all the time. Its not just me, its everywhere you post you sound so angry. Constantly pissed. You'll have lower blood pressure and live longer if you laugh more?

  12. #12
    My apologies all for my less than refined comment. "Wideband is a must! Makes you wonder why you'd ever mess with stock narrowband."

    I simply meant, for overall initial tuning once I learned how to appropriately use a wideband....my job felt way easier and faster to get the motor tuned in (VE side mostly of course). Also verified my PE so, for those reasons I made that comment. Narrowband is more accurate within its range, correct. Hence why it works so well doing its closed loop job. Of course, everyone knows this, and I'm slightly above novice with this stuff.

    PS: My car is a daily driver and guess what.... in closed loop making a dang good 17mpg doing it.
    2006 GTO 403ci lsa heads kooks long tubes corsa ss exhaust OTR intake HPTuned

    2010 GMC Sierra LMM Duramax. Exhaust and tuned

  13. #13
    Senior Tuner kingtal0n's Avatar
    Join Date
    Feb 2017
    Location
    miami
    Posts
    1,103
    Quote Originally Posted by Stroked06Goat View Post
    My apologies all for my less than refined comment. "Wideband is a must! Makes you wonder why you'd ever mess with stock narrowband."

    I simply meant, for overall initial tuning once I learned how to appropriately use a wideband....my job felt way easier and faster to get the motor tuned in (VE side mostly of course). Also verified my PE so, for those reasons I made that comment. Narrowband is more accurate within its range, correct. Hence why it works so well doing its closed loop job. Of course, everyone knows this, and I'm slightly above novice with this stuff.

    PS: My car is a daily driver and guess what.... in closed loop making a dang good 17mpg doing it.

    The truth is modern stand-alone computers do not use narrowbands. Only widebands are used for closed loop.
    The narrowband is obsolete. No longer needed. Haltech, Aem, Motec, MS, PFC, etc... It is not included with wideband closed loop systems.

    For some reason people on this forum are stuck in the past. They think just because the ECU has some capability that it must be enabled for some reason.
    Just because somebody gives you a gun, doesn't mean you have to use the gun.

    Using ECU features just because they are there, without thinking about it, is heuristics mistake, a sign of hubris.

    If you stop and use your brain for a minute (which you already did but others refuse to do) You will notice that closed loop narrowband is an archaic, unneeded, unwanted technology no longer found in modern tuning ECU and serves no purpose other than to correct for tuning mistakes. If you can't tune an ECU properly then you need the closed loop narrowband to at least make up for the mistakes you made. Its like the anti-tuner, a lazy methodology which has been abandoned but a small group of individuals still use just because its there.

  14. #14
    Senior Tuner kingtal0n's Avatar
    Join Date
    Feb 2017
    Location
    miami
    Posts
    1,103
    Quote Originally Posted by Stroked06Goat View Post
    Narrowband is more accurate within its range, correct.
    I don't know who started this rumor but its crazy talk perpetrated by people who wish this was true.

    A wideband has a narrowband inside it. They are literally narrowbands with an added fluid pump used to determine how much fluid is required to bring the a/f ratio back to 14.7 and by using some control theory mathematics it can calculate true a/f ratio of the fluid. Air is a fluid in case you are not sure.



    Some people need closed loop because they are not great at tuning yet or don't want to put forth the full effort to tune the ECU for every possible situation it will encounter, its fine if you don't want your life to revolve around tuning an ECU for years trying to nail down a perfect tune. I get that some people just want to be in and out and done and closed loop will help with that. I use it for friend's cars because I won't always be there to re-tune the ecu everytime the seasons change.


    nevertheless,
    When a college professor is teaching engineering freshman they do not hold back the higher level materials to spare students from the big picture. In my TA with college engineering freshman they get hands on with microcontrollers, arduino and sensitive electronics equipment, soldering and build projects to dive headfirst into the modern world. I've develop software applications for 'tuning' various kinds of electronic ECU (microcontrollers which operate various devices, not just combustion engines) superior to what is available because the combination of mechanical, tuning, and software/electronics engineering is rare apparently, or maybe I just care more. You have to really care about something, the code, efficiency, the perfect circuit to suite... There are control theory experts who have no knowledge of combustion engines that can tune microcontroller far superior to what I can do. But I am often the only one of those programmers with 25 years of tuning combustion engine experience that knows how a carb and points work. They can know all the control theory and programming in the world and still not be able to develop as useful and powerful application for combustion engines as I can because it takes combined experience of the mechanical aspects not just the electronic side of things.

    If I wished to, I could waste my time to develop an VE auto-tuner application for HPtuners that uses widebands and narrowbands, it will collect data array and tune while you drive from revision to revision. Then people will use my auto-tuner ,so easy, and inside the software it will say "Use of wideband is far superior to narrowband with tuning software, it is recommended you remove the narrowbands and only use wideband" and people will finally stop trying to tune using the narrowbands all together and this whole nonsense about narrowband tuning will finally be exposed more fully.
    Even if you use closed loop w/ narrowband it can still be tuned more efficiently and effectively using the wideband. Since, you know, its just a narrowband inside anyways.

    Additionally, and I don't consider this preaching, just personal opinion: There is no issue with a properly tuned ECU running in open loop, always driving in the same conditions for years in my experience with ten or 12 different type of ECUs that I've done it with.
    If perfectly tuned then its perfect tuned. There is no other way I Can simply state the truth. Yes if you take the vehicle somewhere new the closed loop is helpful- but that is a personal, individual situation, not a tuning blockade for most who drive their vehicle in the same conditions all the time.

    It takes more effort to tune for full open loop, and maybe we like to be lazy, not everybody wants to spend their lives learning how to tune an engine for years and years. I am merely fascinated with it. Obsessed, actually.
    Only reason I don't develop software for tuning VE is because its very easy to tune a VE map, the easiest part of tuning the engine is the VE table. I don't think we need an auto tuner for that, what a waste of time. To novices it may seem like a big deal but VE is by far the simplest easiest thing of all in tuning software. It is practically a linear graph.
    Its the rest of the ECU that needs careful difficult tuning for which a simple video would suffice, and HPtuners experts to help with.
    To make the old guys happy, I will like to be wrong then. Narrowbands are godly tools. Keep using narrowbands people nothing to see here. Tal0n out
    Last edited by kingtal0n; 06-04-2022 at 02:20 AM.

  15. #15
    Advanced Tuner
    Join Date
    Apr 2019
    Location
    Parts store
    Posts
    291
    Some may find this useful in a discussion of NB and WB sensors. https://www.youtube.com/@GoTechTraining has some very good YouTube videos.


    https://youtu.be/wZc-zCr2QnE Narrow band explained.

    https://youtu.be/aPtY5FiGMAE Wide band and how their use on the vehicles is very different from what you see on the Narrow band channel in OEM feedback loops.

  16. #16
    Advanced Tuner
    Join Date
    Mar 2020
    Posts
    375
    Talon, when you said you wont use it for friends cars because you wont be there to RE tune it when the seasons change, you explained right there why the CL system is important, and why we use narrow bands in part throttle tuning. I wont, and dont want to be there for every customers car at every season change to re tune it. I want the car to do it. As designed.

    You have a multi port carburetor that you constantly have to monitor and screw with

  17. #17
    Senior Tuner Higgs Boson's Avatar
    Join Date
    Mar 2010
    Location
    Texas Hill Country
    Posts
    3,296
    More modern ECMs use widebands for closed loop, that is true.

    This is the GenIV ECM section where all the ECMs use narrowbands for closed loop.

    Yes, you can flip to open loop permanantely with a wideband, but that is not closed loop.

    If you want to run a GenIV GM ECM in closed loop it's going to have to be with narrowbands.

    Talking about narrowband inferiority and using closed loop in this section is simply resisting reality.
    Other ECMs, sensors, and logic is irrelevant and purely academic, wouldn't expect anything else from a professor.

    I love me a good academic discussion as long as it's disclosed as such and not to be argued from a real world functional mindset.