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  1. #1
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    Default Air fuel changes? Turner cats. 95 supercharged ta


    . .. [COLOR=#000000][FONT=UICTFontTextStyleTallBody]https://youtu.be/Jq-z1FI3bQQ
    how do I change my air fuel ratio at wide open throttle. Do I just play with the %change fuel/air ratio vs. rpm at wot. (Higher number more fuel, lower number less fuel?)
    From what I was read on google doesn’t make sense, some one even has a excel spreadsheet but when I put in my numbers it is not what my wife band is showing.... so I’m doing something way wrong...
    thanks this is completely new to me


    EE hack wideband pin27d to log ( the 1st photo in the vid)
    Turner cat cels to change tune
    Last edited by TheFknJm; 05-28-2018 at 12:51 AM. Reason: Color change

  2. #2
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    Default

    Yes, higher numbers in the %change tables mean more fuel, lower numbers mean less fuel. The numbers from the coolant and RPM tables are added together and used to adjust AFR.

    Say you had 10% in the coolant table and 5% in the RPM table at a given temp and RPM. 10% + 5% = 15%, so your multiplier would be 1.15. Take stoich (14.7), divide it by the multiplier, and you have your calculated WOT AFR... 14.7/1.15 = 12.78 AFR

    The only way of really knowing the AFR is with your wideband though. You can't assume that the MAF is dead nuts accurate, all of your injectors flow the same, all cylinders are perfectly equal, etc. The calculated AFR on one of my cars is about 12.2, but the wideband reads 12.8. On the other car the calculated AFR was 12.9, but the wideband read 12.6. I have AEM Uegos in both cars which are accurate to +/- 0.1 supposedly. Tune, check the wideband, and retune accordingly.
    Last edited by Catmaigne; 05-28-2018 at 01:17 AM.
    96Z M6, ERE-383 #60, AFR 210s, LE cam, 9", Procharger D1, ???whp
    95 Roadmaster T-56 swap, LE1s, baby cam, 4.56s, "The Cammaster"
    95 Firehawk hooptie, bolt-ons and suspension

  3. #3
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    You can scale the afr table, then also raise the maf tables by percentages (multiply table by 1.15 for example to add 15% more fuel) until the maf pegs, then add in the power enrichment and ve percentage tables.

    Sent from my SM-N950U using Tapatalk
    2021 Charger Scat 392
    1994 Firebird Formula 381 stroker - Carrying the torch! - 9.90 @ 134.3mph on a 200 shot

    The wrench/driver for LTConvert's 94 Z28- Ellwein 383/LE Trickflows/ D1SC / CPT Ultra Pro Race 4L60E
    10.78 @ 125mph. Shooting for 9.99 for Frank Cahall!

  4. #4
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    And you removed the FMU, and updated tune for 60 #/HR injectors?
    SOLD - GONE TO A (VERY) GOOD HOME ! - 94 Formula A3+1: 381ci forged stroker - Callies Stealth, Oliver 5.85 billet rods, BME nitrous pistons / CNC LT4 heads / CC solid roller / TH400+GearVendors OD / 4.11 Strange 12-bolt / 300-shot N2O / Spohn Suspension / roll bar / MoTeC M48 Pro engine management system /a few other odds 'n ends.

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  6. #5
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    Default

    Quote Originally Posted by Injuneer View Post
    And you removed the FMU, and updated tune for 60 #/HR injectors?
    Yes fmu is gone. 60# injectors in and changes injector constant.

    I believe that was done correct ended up with a number like 63.4 or something
    Last edited by TheFknJm; 05-28-2018 at 10:58 AM.

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  8. #6
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    Sounds like you multiplied the 60 #/HR flow rate by the correction factor for running 2.7 bar (39.15 PSI) flow rated injectors at 3 bar (43.5 PSI) pressure. Are they “Ford” injectors?
    SOLD - GONE TO A (VERY) GOOD HOME ! - 94 Formula A3+1: 381ci forged stroker - Callies Stealth, Oliver 5.85 billet rods, BME nitrous pistons / CNC LT4 heads / CC solid roller / TH400+GearVendors OD / 4.11 Strange 12-bolt / 300-shot N2O / Spohn Suspension / roll bar / MoTeC M48 Pro engine management system /a few other odds 'n ends.

  9. #7
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    The injectors are Siemens Deka high impedance (long style) I don’t know much about them they came from the gentleman I bough the kit from
    The specs are :
    Coil resistance 12.5 ohms
    Static flow rate @ 43.5 psi (300kpa) w/gas : 60lb/hr =630cc/min =453g/min
    Gain 0.11ms/ mg
    Offset 0.55ms
    Turn on time @14Vdc 1.14ms
    Turn off time 0.85ms @600kpa
    Deka 4 (deka Iv)
    30* spray come

    Also had other info @87psi but I didn’t look at that since I’m no where near that

    For the life of me I can’t find the paper I wrote down how I got the constant of 63.35 ( that’s what it is set at I just looked)
    What I did if I can recall is took fuel pressure at idle that was 43.5 did some math and came up with the 63.35 number.
    With the vacuum off the stock regulator my pressure was about 49 psi... damm I wish I could find that paper I wrote it all down on

  10. #8
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    If your “no vacuum” pressure was 48.5 PSI, you probably did this:

    48.5 / 43.5 = 1.115

    Square root 1.115 = 1.056

    1.056 X 60 = 63.35

    Is your fuel pressure regulator stock? GM spec is 41 - 47 PSI. 48.5 is a bit high, if that was after removal of the FMU. And you deleted (or bypassed) the inline booster pump?
    Last edited by Injuneer; 05-28-2018 at 06:35 PM.
    SOLD - GONE TO A (VERY) GOOD HOME ! - 94 Formula A3+1: 381ci forged stroker - Callies Stealth, Oliver 5.85 billet rods, BME nitrous pistons / CNC LT4 heads / CC solid roller / TH400+GearVendors OD / 4.11 Strange 12-bolt / 300-shot N2O / Spohn Suspension / roll bar / MoTeC M48 Pro engine management system /a few other odds 'n ends.

  11. #9
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    Yes stock regulator and after fmu and booster pump taken out.

    So I was able to play with the %change fuel/air vs rpm at wot and brought the fuel in little better. Still really rich but moving in the right direction. Starts at 12.2 at 2500 rpm works it’s way to 10.7 at 6k..

    Thank everyone for all the help I really appreciate it

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