Results 1 to 5 of 5

Thread: Injector Duty, Torque and Cyl Airmass SPIKE while tuning VVE

  1. #1
    Tuner in Training
    Join Date
    Jan 2020
    Posts
    27

    Exclamation Injector Duty, Torque and Cyl Airmass SPIKE while tuning VVE

    Anyone have any input on this? Everyone I have talked to has never seen it before.

    I am dialing my VVE table - MAF is turned off.

    This is a C6 LS3 with just headers.

    I see no spike in my VVE table.. Completely perplexed as to what would cause this.

    Duty is 200%
    Cyl Airmass is 3.39
    Torque is around ~1600ftlb

    This has happened 3 times. Finally caught it on a log.

    Spike.png

    Spike Chart.png

    Spike Graph.jpg

    Spike Table.png


    Tune attached.

    Step 5 new zone boundries.hpt
    Last edited by bgreen; 07-07-2020 at 05:11 PM.

  2. #2
    I’ve got a very similar issue. Did you find the culprit?

  3. #3
    Potential Tuner
    Join Date
    Dec 2020
    Posts
    5
    Can you post up your spark map? You could use a whole lot more ignition timing but this looks like a misfire/ cam bucking. The other thing I would note is you?re at 100% throttle but only 89kpa. Do you have a dirty air filter or at high altitude?
    Last edited by Elgazzar; 12-30-2020 at 01:05 PM.

  4. #4
    Advanced Tuner
    Join Date
    Jun 2014
    Location
    Boulder, CO
    Posts
    201
    Your fuel pressure across the injectors table is almost flat -- do you have a MAP referenced FPR? But I don't see that affecting the crazy air flow spike! Your trans output max torque setting is 12,084 lb/ft, I thought the max value the ECU allowed was 6042. It's perhaps suspicious that it's exactly twice 6042? But I've no idea if that could cause the reported airflow spike, either. And I agree that the timing maps are very conservative, even for a boosted engine.

  5. #5
    Senior Tuner LSxpwrdZ's Avatar
    Join Date
    Dec 2008
    Location
    on the Dyno
    Posts
    1,825
    It's in your VVE...

    If you add MAP axis in 1kpa increments youll see a huge increase in GMVE from 90kpa -> 89kpa. Also zero out the prediction coefs.

    VVE Issue.png
    James Short - [email protected]
    Located in Central Kentucky
    ShorTuning
    2020 Camaro 2SS | BTR 230 | GPI CNC Heads | MSD Intake | Rotofab | 2" LT's | Flex Fuel | 638rwhp / 540rwtq
    2002 Camaro | LSX 427 | CID LS7's | Twin GT5088's | Haltech Nexus R5 | RPM TH400