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Thread: 2017 Sierra 6.2 VVE start of tuning questions

  1. #1
    Tuner
    Join Date
    Dec 2011
    Location
    Springfield MO
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    76

    2017 Sierra 6.2 VVE start of tuning questions

    Hi all, I on and off tune my stuff and helped a couple local friends out so I only dabble in this but it has been gen 3 stuff and as noted the gen 5 is much different. I am reading and learning. I have only had this Sierra for a few weeks I assumed it has not been tuned but I am happy it runs well as is but I want to do some to it.
    The tune is what I am starting with and untouched so the MAF is not failed or anything yet I just wanted you to check the log and make sure it looks right before I fail it then start my data collection.
    Seeing most of this short log has negative LTFT also shown on my VVE graph does this indicate it definitively needs some tweaking in this area? Or would you expect this to change when I isolate the MAF and the SD side? I believe I cant use this as is but need to fail the MAF to start.
    It is also very cold here this morning so I dont know it that will affect this or not?
    Any other thoughts or suggestions would be great!
    I also wanted to add in the log I kept the transmission in the "L" so I didn't go into the V4 mode. So for the real tuning should I stay in V8 mode? I know there are 4 VVE tables and have read to just do one and copy them all to be the same? That seems strange but I wouldn't know how to populate the other 3.
    Thanks
    Dave
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    Last edited by Custom 68; 01-20-2020 at 01:25 PM.

  2. #2
    Tuner
    Join Date
    Dec 2011
    Location
    Springfield MO
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    76
    I had used this post https://forum.hptuners.com/showthrea...al-VE-Vehicles
    for my setup so kudos and many thanks to schpenxel for this.
    Dave

  3. #3
    Tuner
    Join Date
    Dec 2011
    Location
    Springfield MO
    Posts
    76
    This truck is all stock and don't have any plans to change that but the more I read on here the more issues seem to come up regarding VVE tuning. It seems to be tied to the boundary zones. It seems as I read they are more on the boosted applications. Is this VVE tuning the best place to start? I haven't purchased the credits yet as I am still learning and deciding if this is something I should tackle. When I did my turbo Gen3 I just worked slow and made changes until it all seems right.
    Thanks
    Dave

  4. #4
    Advanced Tuner
    Join Date
    Mar 2011
    Posts
    436
    What mods have you done to it? It certainly looks to be a little rich. Before you begin altering the VVE and MAF tables, check the reported ethanol content in the scanner. Most of the GEN 5 applications do not have a fuel composition sensor now. They simply estimate the ethanol percentage by using the oxygen sensors. You can simply disable the Virtual Flex Fuel sensor in the tune and fix this issue in these cases.

  5. #5
    You can disable DOD in the tune under Fuel- Lean/Fuel Saving while you are tuning so you can drive normally. You will also want to log MAF g/s as well as MAF Airflow. It looks like your VE airflow is, on average, below your Dynamic Airflow.

    If you make changes, be sure to reset your fuel trims before logging again.

  6. #6
    Tuner
    Join Date
    Dec 2011
    Location
    Springfield MO
    Posts
    76
    Thanks guys, I have not done any mods to this other than installing a catch can but I wouldn't count that... I've only had this a month so I am still learning about it but it seems peppy being the 6.2. I have not even unlocked the tune only read it and a couple scans.
    The tune does indicate it is a virtual sensor but thought I might at some point add the actual sensor but I can turn this off till then.
    I thought it all looked a bit rich just based on what I saw but wanted to make sure I had the correct sensors. It seemed like there is a normal MAP sensor then a high res MAP. I chose the "standard" (SAE) channel.

    Since it takes 4 credits to unlock this I was trying to get my process in order and decide what all benefits I can gain with me tuning this. I do have that slight stumble or hesitation at take off so I would like to address that and just make it a bit more efficient. Plus I cant seem to leave these alone.
    I had fun tuning my turbo gen 3 I have in my 68 Chevy pickup.
    Any more thoughts would be great.
    Dave