AFR Tuning

Posted by Rageful, Jul 6, 2011
Newbie Forum - Beginner/newbie/general DSM modification questions. First mods, how to run 10's when you haven't run 12's yet, any tech question that doesn't fit in another tech forum.

  1. Rageful

    Rageful Probationary Member

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    Hazleton, Pennsylvania
    20g turbo(20psi), 255 walbro, 560cc evo injectors. Rest of Mods on profile.

    I do know I am in need of a afpr, and its on the list just before the professional tune this summer.

    Car has a 98ecu with tactrix cable already setup, so tuning software of choice is:
    ECUFlash/CeddyMods with EvoScan for logging software.

    Idle is 14.7:1 So I am alright at this aspect.
    During DD car is 11.9-15.1 So This isn't bad imho.

    During WOT car goes into 10:1 (Gauge Does Not Go Below 10, so it is a possibility it is lower)

    Is there anything I could do at this time besides the afpr? (relatively new to tuning)

    In Certain Areas My A/F tables go down to as low as 9.1. Should I start by just adjusting my A/F Tables slowly? Or Am I hopeless until I get the afpr.

    Another Question:
    20g/255walbro/560cc. Is this A/F setup fine with that size injectors and my other mods? Looking for 350-425whp.
    #1
  2. snowborder714

    snowborder714 Moderator

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    Downingtown, Pennsylvania
    You should have a wideband o2 sensor before really tuning AFR's.

    Any idea what your IDC %'s are? I can't imagine being able to even push the 20g on 560's without easily overrunning them.
    Last edited by a moderator: Jul 10, 2014
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  3. Rageful

    Rageful Probationary Member

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    Hazleton, Pennsylvania
    I do have a wideband. AEM Wideband O2 Air/Fuel UEGO Gauge Kit - Part Number: 30-4100 - Sparktec Motorsports

    I'll check the IDCs today when I log it. But I figured as much about the 560s duty cycle.

    What would you recommend? 650/700s?

    What ECU Changes would I need to do to accommodate for larger injectors, other then going into EcuFlash and setting the new cc size. As in, to keep me stable until the tune day.
    #3
  4. mattasi

    mattasi Proven Member

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    Springfield, Oregon
    For pump gas I would recommend 880cc. I have a 20g at 24psi with 660cc injectors and they are pretty maxed out..
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  5. e_miller81

    e_miller81 Proven Member

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    Elkhart, Indiana
    You only want to run about the 80% Injector duty cycle. I would use this calculator to help determaine the injector size

    RC Fuel Injection

    I forgot to mention that if you plan on running E85 you can actually get more more because it can take more igntion but it also takes about 20% more fuel to do so.
    Last edited by a moderator: Jul 10, 2014
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  6. Rageful

    Rageful Probationary Member

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    Hazleton, Pennsylvania
    Ran 3 sets of 3rd gear pulls.

    note: Throttle Cable is a bit loose, have planned to tighten it this weekend when me and my friends hang out.

    Mechanic Installed Fuel Rail ONTOP of Throttle Cable on my last visit ~_~.

    Highest IDC was 70.2% at 85% TPS.

    Car log when as low as 9.8 AFR, don't have load (im at work :sneaky:)

    Car ran like a beast tho. (1st actual run since head work)
    #6

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