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V6 Turbo for Economy

Discussion in 'Newbie and Basic Turbo Tech Forum' started by Cbakerbike, Apr 16, 2024.

  1. tbird

    Sep 1, 2004
    How many can say they spend timing tweeking fuel and timing tables for milage?
    Most dont realize light cruise can be near 16 afr and 50 deg. timing yet most are just content with 14.0 afr and under 40 deg.
    So my question would be , was the NA combo wrung out before the turbo was on it.

    Like ive said before, car manufactures are emission over mileage these days because the ill directed EPA is up their ass.
    ummduh, B E N and jbliss15 like this.
  2. B E N

    Nov 22, 2016
    The real modern stuff will run even higher timing than that. My supercharged 3v will run 56-58° under cruise, coyote on a stock control pack tune will hit the same. If you have the octane to keep the knock sensors happy mid 50s is real common on modern stuff (at least from what I have seen from Ford and GM cruise state data logs).

    When I had my Raptor it was so detonation limited at cruise I would regularly see the ecu retard bringing it down to the low 30s°, keep in mind I often cruise at ≈5000 feet of elevation where the air is garbage and your effective compression ratio is down. I switched over to e85, and built a flex fuel tune. Timing came up to mid 50s and I saw little difference in mileage between E85 and midgrade fuel on the highway, even with the huge energy density deficit. Timing can make a big difference. Colder combustion chamber probably helped too. Economy was way up because the E is so much cheaper per gallon.

    AFR and timing work together. When you are running an engine lean the fuel molecules are packed less densely, they transfer the flame front more slowly so you need more timing. Same reason you retard timing under boost, fuel is packed more tightly and it takes less time to combust the mixture. That also means when you are running high vacuum (cruise state) the molecules are more spread, so you need more timing to cruise efficiently. You need to keep the symbiosis in a good place when you start tuning for max fuel mileage.

    Greg Banish states in 'Designing and tuning high-performance fuel injection systems': "Most engines see less than a 5% decrease in steady state fuel consumption with lean burn conditions". I didn't quite understand at first, the math doesn't make sense when you look at the amount of fuel used per revolution. He goes on to explain once you get far enough away from optimum AFR for power (around 12.6:1 is his stated optimum) the torque loss overcomes what you gain from any further leanness. The engines effective load goes up when torque decreases, vacuum decreases, more fuel is going in per stroke. Just like everything else in engine design it ends up being a balancing act.

    He suggests 15.4:1 (on a 14.7:1 stoic gas scale, most fuel now has 10% ethanol and is stoic around 14.2, so you should really be shooting for something around 14.8 as optimum cruise AFR). My experience bears out his numbers pretty closely on a handful of different engines. I wouldn't run over 14.8 on a modern engine, with modern oxygenated fuel, and I wouldn't run over stoic unless you have some sort of datalogging, more sophisticated is better. I think the risk is just too great, and there is little to gain.
    tbird likes this.
  3. F4K

    Jan 7, 2020
    With all due respect

    That guy has been bullying me since 2020 Following me, telling people I am a troll and to ignore me, telling me that Im on ignore yet continuously responding to my posts while coaching others that I am the troll.

    And I have never said a word against him or any offensive actions since the beginning of his atrocious bullying behavior, because I am not a bully and I am not an aggressive online person who ever attacks people with name calling and slander the way he has done. It is his personality to do these things you are about to see, his own spirit tarnished with these acts of jealousy and spite, allowed to fester and permeate, corrupt online community.

    Unsportsmanlike conduct:
    Bad manners. Rude. Unacceptable. since 2020

    Coaching others to put me on ignore



    The bandwagon - They claim I copy and paste!




    The only thing I have done is speak truth.
    You can clearly see that I have been attacked relentlessly without provocation for years, I show evidence

    That is his image he is destroying, not mine. This recent, blatant copy/paste adds another level of evidence and irony to his persona. He lied to somebody, made incorrect unintelligible comments about it, and they caught it, they turned out to be much smarter than he assumed which seems to be a trend, and he ignored them in response and probably called them a troll at some point. Nice morality, setting a good example of how to behave for others.

    There is nothing I can do to help him. That is YOUR job moderation to keep these type of behavior off your forums, Moderation job is to step in and tell him to stop slander, stop calling intelligent doctors on your forum a troll and telling people to ignore them just because he is envious. I have kept my mouth shut and taken the beatings of the trailer park kids but one by one I came to their houses and punched them alone.

    He has ruined his credibility and the truth in the open. Signs point to shady deceptive bully with anger envy and spite issues against anybody more intelligent.
  4. F4K

    Jan 7, 2020
    On the subject of who is a troll

    There are many individuals that have the intellect to read, interpret, understand the sense of my writing.


    frequent diagnostics on numerous forums

    Developed the first auto-tuning software algorithm for Holley ECU 2003

    I want more examples
    Supraforums, moderator approved

    Thirdgen, GM engineer approved crankcase evacuation details

    Zilvia, ASE certified mechanic quoting my ancient post

    LS1tech, they love my advice when it doesn't make them feel stupid

    Smart people, as engineers on corvetteforum

    4l80e conceptualization for diag

    I have more total weight diagnostic postings strewn across 30+ automotive forums than any single person I've ever met.
    To call your most highly educated, highly experienced, well known automotive tuning mechanic a troll is well. It is what it sounds like, absolutely ridiculous. And this just keeps going on... on the internet you can say whatever you want. Slander whoever you want. And there is no consequences. Well, except for the evidence you leave behind. Shit I love evidence. Let me get some evidence



  5. jbliss15

    Mar 8, 2024
    Cool story bro
  6. Robb235

    Aug 15, 2012
  7. TurboSnake281

    Dec 13, 2021
    That’s what she said
  8. TTF/Ken Staff Member

    Dec 31, 2011
    When I start seeing checks in the mail written by you, then you can tell me what my job is. Until then, you're a guest, and don't direct the site.
    jbliss15 and Wallace like this.
  9. jbliss15

    Mar 8, 2024
    I tell women I'm an intelligent doctor
  10. gruntguru

    Feb 1, 2019
    The answer to the OP. Cut off 2 or 3 cylinders and boost the remainder back to the power level you need. That's what the OEMs do. (Might be simpler to just buy one of their engines.)
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