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Thread: Timing values higher than set.

  1. #1

    Timing values higher than set.

    2007 Grand Prix supercharged.

    I have a minor knock issue that I am trying to correct. Problem is that when I lower the spark table in my tune is showing higher in the scan along with knock tard. My modifiers all look fine and should not be adding. I am not sure where to look. Any help is appreciated!


    12-14-19 trim.hpt12-14-19 scan.hpl
    2017 Buick Regal Sport Touring 2.0t

  2. #2
    Tuning Addict 5FDP's Avatar
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    It's going to be very tough to remove all the minor amounts of knock you see. It's not consistent and the values are rather small cause no real harm.

    I can't follow the timing curve exactly because you are missing the cylinder airmass channel and the graph isn't setup to log the timing curve like the table does in the editor. Where the cyl/a is on the column axis.

    Other than PE adding is maybe 1-2 degrees of timing because of the AFR spark adder, the max torque timing can reason the timing differs. The values in there are different than the high/low timing table and the computer could be referencing that table to help pic ignition timing.
    2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.

    If you don't post your tune and logs when you have questions you aren't helping yourself.

  3. #3
    Thanks 5FDP! at what knock value should i start to concern myself with? I will try to adjust the graph and add cyl/a channel
    2017 Buick Regal Sport Touring 2.0t

  4. #4
    I don't see anything in the channel for cyl/a other than the maf cylinfer airmass that is already logged. My chart is setup the same as the editor. I am not sure what to set there.
    2017 Buick Regal Sport Touring 2.0t

  5. #5
    Tuning Addict 5FDP's Avatar
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    Rogers, MN
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    I always had random 1-3 degrees of knock at low to medium throttle, low boost area's. Could never tell if it was real or just from the harmonics of the engine/vehicle.

    At full throttle my car made 8-9psi and if I saw 1 degrees of knock with little spikes higher I didn't concern myself because the computer can pull that small amount back. Seeing 3+ degrees constantly would be worry to me. I ran around a 11.0 air fuel ratio with anywhere from 13-15 degrees timing on pump 91 or 93 fuel, it was pretty good and I kinda just stopped messing with it once I knew the knock was very minimal if at all.
    2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.

    If you don't post your tune and logs when you have questions you aren't helping yourself.

  6. #6
    Thanks for the information! I really appreciate it!
    2017 Buick Regal Sport Touring 2.0t