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Thread: WOT AFR & Timing Tuning

  1. #1
    Senior Member blsnelling's Avatar
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    Default WOT AFR & Timing Tuning

    I kind of started this topic in the thread about getting my LC1 working, but want a thread dedicated to WOT AFR and timing tuning. Hopefully this thread will end up usedful to other newbies like the idle thread.

    This run was mad on 93 octane fuel, from where I always buy it. There was no audible pinging at all. For those that haven't been following, I've already completed the CalcVE tune on my Main VE table and MAF table.

    I'm most concerned with getting rid of the KR. Where do I start?



    Looks like my WOT AFRs above 4,000 RPMs go from 12.30 to 12.86, getting richer as the RPMs climb. Isn't that on the safe side of a good tune, and can therefore be eliminate from being a cause of KR?

    How about getting rid of that KR? How much KR does it take to hurt an engine? I know I'll be tuning it out, but just curious. Each WOT run in this log was different. One had nearly no KR, another maxed at 4, and then the last about 6. Is there a map you guys use to tune out KR?

    Is the Spart High-Octane Table the one I'll be using to adjust WOT spark timing in order to reduce KR? What's the Base Spark in Gear table for?

    Lots of questions. Take your pick

    Log file
    AFR_002.efi

    .tun file
    My Modified_016.tun
    Last edited by blsnelling; October 29th, 2010 at 06:02 AM.

  2. #2
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    Quote Originally Posted by blsnelling View Post

    Looks like my WOT AFRs above 4,000 RPMs go from 12.30 to 12.86, getting richer as the RPMs climb. Isn't that on the safe side of a good tune, and can therefore be eliminate from being a cause of KR?
    the AFR u mentioned should be fine.

    Quote Originally Posted by blsnelling View Post
    How about getting rid of that KR? How much KR does it take to hurt an engine? I know I'll be tuning it out, but just curious. Each WOT run in this log was different. One had nearly no KR, another maxed at 4, and then the last about 6. Is there a map you guys use to tune out KR?

    Is the Spart High-Octane Table the one I'll be using to adjust WOT spark timing in order to reduce KR? What's the Base Spark in Gear table for?

    Lots of questions. Take your pick
    you need first to confirm whether it reads from low or high octane table. Real KR will damage the engine even if it is 1 only. Sometimes, knock comes because of a lot of other reasons, like cat clogged, exhaust vibrates...etc

    The car is reading from hi and lo octane tables as soon as you leave idle mode. KR increases if the value of IAT & ECT increases so u need to look at the timing temp tables to confirm enough retard at hi temp condition.
    Regards,

    Odd Boy

  3. #3
    Joe (Moderator) joecar's Avatar
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    The pid ASPARK indicates the sliding-scale blend between the HO and LO spark tables.

    +1 knock happens for many reasons and has many sources.

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    - If you run 93 octane all of the time copy the High Octane Table to the Low Octane. Looking at your log and tune there is a 4 degrees difference at WOT between the two. The burst knock fast attack values are also set 4-5 degrees in the 4000 rpms columns and above. You can reduce them slightly as well.

    - Your commanded AFR is 11.90-12.05 at WOT, but the WB reads 12.63 (on average) and hits 13.09 in some areas so you are at least 5% lean. If you want 12.63 at WOT, then set the PE to that value and tune accordingly. For sake of simplicity (and for sanity for now) set the PE values to one value for the majority of the table (example 2400 rpms and up). This will make it easier to tune WOT as you learn.

  5. #5
    Senior Member blsnelling's Avatar
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    You mention that I'm running leaner than commanded. I'm afraid I'm maxing out my 8.1L truck injectors then. I did notice before that they're were up to 95% duty cycle.
    '01 ECSB 4x4, '04 6.0L LQ4 Shortblock, 243 Heads Milled .035 11:1 Compression, Pac 1218 Springs, Yank PT3200 Stall, Comp Cam 220/224, .581/.581, 112LSA, LS7 Lifters, TBSS Intake Manifold, Edelbrock 3864 90mm T-Body, Doug Thorley LT Tri-Y ceramic headers, Flowmaster 50 SUV, LS1 e-fans, Airaid MIT, Complete valve body build up, 4.30:1 Gears, 33/12.50-17 Tires

  6. #6
    Senior Member blsnelling's Avatar
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    I've copied high octane over low octane, since I will be always running premium grade fuel. I've also set B3618 to command 12.61 AFR in PE mode. Considering that I already have 6° of KR do you recommend pulling some timing in the high octane table? If so, I'm not sure what cells to mess with.

    My Modified_020 Timing.tun
    '01 ECSB 4x4, '04 6.0L LQ4 Shortblock, 243 Heads Milled .035 11:1 Compression, Pac 1218 Springs, Yank PT3200 Stall, Comp Cam 220/224, .581/.581, 112LSA, LS7 Lifters, TBSS Intake Manifold, Edelbrock 3864 90mm T-Body, Doug Thorley LT Tri-Y ceramic headers, Flowmaster 50 SUV, LS1 e-fans, Airaid MIT, Complete valve body build up, 4.30:1 Gears, 33/12.50-17 Tires

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    Quote Originally Posted by blsnelling View Post
    I've copied high octane over low octane, since I will be always running premium grade fuel. I've also set B3618 to command 12.61 AFR in PE mode. Considering that I already have 6° of KR do you recommend pulling some timing in the high octane table? If so, I'm not sure what cells to mess with.

    My Modified_020 Timing.tun
    I didn't realize your injectors are maxed out. In that case don't even bother with WOT tuning and leave the WOT PE as is until you get new injectors.

  8. #8
    Senior Member blsnelling's Avatar
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    That's what I was afraid of, lol. Time to upgrade the upgrades
    '01 ECSB 4x4, '04 6.0L LQ4 Shortblock, 243 Heads Milled .035 11:1 Compression, Pac 1218 Springs, Yank PT3200 Stall, Comp Cam 220/224, .581/.581, 112LSA, LS7 Lifters, TBSS Intake Manifold, Edelbrock 3864 90mm T-Body, Doug Thorley LT Tri-Y ceramic headers, Flowmaster 50 SUV, LS1 e-fans, Airaid MIT, Complete valve body build up, 4.30:1 Gears, 33/12.50-17 Tires

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    What psi are those injectors rated at? Do you have the stock fuel pump? I didn't look, but did you recalculate the Injector Flow Rate?

  10. #10
    R.I.P Shawn, 1956-2011 WeathermanShawn's Avatar
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    Your PE EQ of 1.13 for E10 (see your B3601) is also quite lean.

    For E10 you need to be closer to 1.16-1.17 (AFR 12.1). Your AFR's are tuned to the wrong fuel type..See:http://forum.efilive.com/showthread....l=1#post103113..E10 Worksheet (post#52).
    2002 Black Camaro Z-28 M6 Hardtop 11.0:1CR 425HP/410TQ SAE (400TQ@3500RPM)
    200cc Heads, 228/232 110+2 Cam, 1 3/4" LT's w/catts, GMMG, Koni Shocks, Hotchkis Springs, 35/21 Sways, 17" ZR1's, 3.90 Gears Roadrunner PCM LM-2 Serial Wideband
    EFILive Closed-Loop MAF/SD Hybrid Tune..


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