AFR Tuning

Posted by Rageful, Jul 6, 2011
Newbie Forum - Beginner DSM modification questions and discussions. Common, repetitive, and general discussions will get dumped here from other tech forums. Unless you're a Probationary member you shouldn't post threads here.

  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
    #2
  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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