Very upset...!

Discussion in 'Dyno Stuff' started by ralphie, Jul 1, 2015.

  1. MOD(S)QUAD

    MOD(S)QUAD Full Access Member

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    For Example:
    15.0:1 = Lean
    14.7:1 = Stoichiometric
    13.0:1 = Rich


    Leaner AFR results in higher temperatures as the mixture is combusted. Generally, normally-aspirated spark-ignition (SI) gasoline engines produce maximum power just slightly rich of stoichiometric. However, in practice it is kept between 12:1 and 13:1 in order to keep exhaust gas temperatures in check and to account for variances in fuel quality. This is a realistic full-load AFR on a normally-aspirated engine but can be dangerously lean with a highly-boosted engine.[/QUOTE]

    Unless I am missing something here, 13.0:1 is still way lean from my understanding
     
  2. VPRPWRD

    VPRPWRD VTCoA Ring Leader Supporting Member

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    The first number is parts air, the second number is parts fuel. Fewer air parts, 13, to the 1 means it is rich.
     
  3. ralphie

    ralphie Full Access Member

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    I thought a good number to shoot for was around 12 under a load...! dang....just when I thought I had a handle on the a/f deal. lol
     
    Last edited: Jul 2, 2015
  4. 505'sFastestViper.

    505'sFastestViper. Full Access Member

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    Justin will get you dialed in
     
  5. Psycho1122

    Psycho1122 Full Access Member

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    This information is correct in a perfect world. A "hunting" 14:7-1 is great when highway cruising under steady throttle (No load). However, our engines do NOT have an efficient combustion chamber and need to be on the rich side to make smooth, strong torque and detonation free H.P. at high R.P.M.

    YES, too lean by about a full point. especially from 4500 rpm to 5500. It does however "nose over" nice at redline.

    Yes. 12.7 / 12.8:1 would be ideal.

    12:8-1 and richer to keep combustion chamber temperatures cooler. Add up to what some say +23 to +25 total ignition advance and KEEP the ratio at 12:8 or just under and your engine will make great N/A power. :)

    Unless I am missing something here, 13.0:1 is still way lean from my understanding[/QUOTE]

    Yes. 13:0-1 is still too lean at WOT.

    Cheers Guys!
     
  6. VENOMOUS1 RACING

    VENOMOUS1 RACING Has Left the Room - Banned from VTCOA!

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    Again he dynoed on nitrous plugs and sounds like overdrive so it surely wasn't an optimal set of pulls. Still unsure why one sheet reads one way and the other opposite? Anyone else see that?
     
  7. ralphie

    ralphie Full Access Member

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    Scott, the dyno sheets that were close-up, were Stealth78's...not mine. we were comparing. His looked good to me. Here is mine.
     

    Attached Files:

  8. VENOMOUS1 RACING

    VENOMOUS1 RACING Has Left the Room - Banned from VTCOA!

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    Duh, I don't know how I missed that.
    I don't like either! His starts off lean and fattens up nicely. You're starts out nice and leans out too much. Both are scary situations but I'd expect your numbers to be close to Stealths on NA plugs and tune corrected.
     
  9. ralphie

    ralphie Full Access Member

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    We'll

    We'll get it. Between Justin, Torrie, Scott and everybody here, we'll, or I should say, they'll get it. To much knowledge not to. Can't wait to get it cammed and dyno-tuned Thnx everybody....!
     
  10. JMB Justin

    JMB Justin New Member Preferred Vendor

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    Got it fixed up, 488whp/486wtq with JMB/PBJ cam and minor tune changes. That's through unlocked 3000 stall converter, 93whp and 84wtq gain over what it made before. I'll post a new thread with dyno chart Monday.
    Justin
     
  11. 505 V10

    505 V10 Has Left the Room - Banned from VTCOA!

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    Question? What does the stall of a converter have to do with max output on a dyno? I am under the impression that stall only affects launch from a standing start.

    Just wondering. Personally, anything without a 3rd pedal is boring to me.
     
  12. ralphie

    ralphie Full Access Member

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    I have no clue. Maybe somebody can elaborate. All I know is, my truck sure runs alot better after the new camshaft got installed.
     
  13. 505'sFastestViper.

    505'sFastestViper. Full Access Member

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    if the stall isn't locked up you have slippage . slippage equals horsepower loss
     
  14. ralphie

    ralphie Full Access Member

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    Justin will have to elaborate on the "unlocked" converter. I wasnt there when they dyno tuned it, so I have no clue what they(Justin, Torrie and Perf. by Joe) did. Hell....had I been there, I'd prob. still been lost..! lol