Results 1 to 6 of 6

Thread: Bouncing AFR, slow o2?

  1. #1
    Potential Tuner
    Join Date
    Apr 2014
    Posts
    7

    Bouncing AFR, slow o2?

    I just would like some opinions if it seems normal or what you may think. The AFR jumps but i cant really feel it surging or anything. Seems like o2 are moving slow. Just was hoping someone can take a look and let me know if it looks okay or something i should try to do?

    01 LS1 with Cam, LS7 MAF, Fast Intake, CNC 243 heads, LT Headers, 4" Exhaust, 4l80e with high stall circle D.
    Attached Files Attached Files

  2. #2
    Tuning Addict 5FDP's Avatar
    Join Date
    May 2012
    Location
    Rogers, MN
    Posts
    13,533
    Take some tune and tune the VE, then switch it to a blended mode instead of just MAF only. Then see how it is. Having both the MAF/VE calibrated is a good idea.


    My preference here but the timing curves should not be mirrored and you could probably setup the idle timing and cruise timing better. The timing values are pretty bland for fuel mileage, it's missing about 10-15 degrees for sure.
    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
    Potential Tuner
    Join Date
    Apr 2014
    Posts
    7
    Okay so I understand do a VE tune I can handle that, but i was searching for "blended" mode to see where the option is and have no idea, please let me know where those options are.

    Now I set the timing lower cruising because when I got the car back from tuner when cruising the car would hang throttle it felt and would go down the road basically without hitting the throttle. Almost felt like cruise control was on. So I pulled timing out and it stopped. Im sure you guys can tell me what else I can do instead of pulling timing. I dont mess much with HP anymore just to mess with this tune on my wifes car.

  4. #4
    Tuning Addict 5FDP's Avatar
    Join Date
    May 2012
    Location
    Rogers, MN
    Posts
    13,533
    The dynamic airflow high rpm on a stock calibration is set to 4,000rpm. Meaning that it will use both the MAF/VE until 4,000rpm and switch to the MAF only above that. Your calibration is set to use only the MAF all the time.
    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.

  5. #5
    Potential Tuner
    Join Date
    Apr 2014
    Posts
    7
    Ok I have my VE table just about done, just wanted to check I should set it to 4000 no higher or lower for any reason? The car has a 4000 stall in it so its very easy even under 1/2 - 3/4 throttle to hit 4000 rpm so not sure if that makes any difference?

  6. #6
    Potential Tuner
    Join Date
    Apr 2014
    Posts
    7
    Updated VE and set dynamic high rpm to 4000 car is good however AFR still bouncing around a bit at cruising. But im not real concerned about that car runs good. You mentioned my low timing while cruising and id like to be able to add timing back into the tune but do you see anything that would keep the rpm to hang while driving? It still barely does it right now at 60-65 mph with converter locked.

    Just was looking at MAF hz and it seems very jumpy.. I believe thats the cause of my AFR jumping.. any thoughts?pull1111.hpl alyson camaro aug 23 2019 emissions updated VE.hpt
    Last edited by zapp109; 08-24-2019 at 05:22 PM.