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Thread: What could cause my boost to exceed my max setting like this? 1.4 sonic E78

  1. #1
    Tuner in Training
    Join Date
    Sep 2021
    Posts
    46

    What could cause my boost to exceed my max setting like this? 1.4 sonic E78

    I am confused, I have my max boost set to 33 (33 - 14.7 = 18 psi roughly) on my 2013 sonic 1.4T, it has larger turbo/cam/intake/exhaust/valve springs/ported head and intake man. Now I understand a few lbs. of boost over the max from the overboost table and surge limits, maybe a couple other tables, and I think that's usually why I run around 21 lbs. or so. However, in my last 2 logs, it will all the sudden take off like a rocket and my boost goes well above 43 (or 28lbs.), my PE is commanding .78 and its hitting like .71 which puts my IDC to over 100% and what looks like unburnt fuel (light grey smoke or vapor) pours out of the exhaust. When this happens, the WG goes erratic then closes as shown in the screenshots. What am I missing? I have a cam swap and its got p0016 (cam crank correlation error) but it runs and revs freely, just wondering if this would cause this kind of chaos? it wont let me try a case learn because the code is present. Is this where I should start (I am working on this), or is this WG DC or something else?

    LOG
    709 boost spikes.hpl

    TUNE
    709, WG, PDelta, Maf leaned up top.hpt

    SCREENSHOTS
    Screenshot (1).pngScreenshot (3).png

  2. #2
    Advanced Tuner
    Join Date
    Aug 2016
    Posts
    386
    I would recommend fixing all known mechanical issues with the vehicle before trying to diagnose the boost control issue. If you have a P0016, then it sounds like you need to go over your cam swap again, and something isn't installed correctly.