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Thread: Anything small holding me back?

  1. #1
    Potential Tuner
    Join Date
    Nov 2019
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    1

    Anything small holding me back?

    Posted over on the bullet about my car just not making what it should be. They directed me to take a look at disabling torque management and KR. I looked into everything a bit but there seems to be some conflicting information on what tables to max and what tables to zero. I have not changed anything in my tune since I had the car tuned by a professional so hopefully it is all correct, but I'm honestly too new to understand it all. I have been watching a number of video guides and I am getting the general gist, but if someone could just look over my tune really quickly to see if there is anything glaringly incorrect it would be much appreciated.

    Here is my original thread on yellowbullet:
    https://www.yellowbullet.com/forum/s....php?t=2605451

    For a short rundown the car is a 99ss camaro running a 0411 pcm.
    - ABS/traction control are completely deleted
    - Rear 02's disabled and swapped with front connectors
    - Running speed density
    - Engine/trans/rear are built and can withstand all TQ management and abuse modes disabled
    - The rest of the details you may need are listed in the link, most importantly its an auto car.

    Original_from_Tuner.hpt

    Thanks in advance

  2. #2
    Tuning Addict 5FDP's Avatar
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    May 2012
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    Rogers, MN
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    Was there any attempt to run different air fuel ratio's?

    The tune is asking for 12.93 but if you are seeing 13.0-13.4, the airflow model is kinda far off. Sometimes engines will make more torque with a fatter AFR down around 12.5.


    The engines drivetrain abuse is still active but hard to say if that is a cause of anything.

    You'd also benefit from applying the 1 bar speed density enhanced OS upgrade. It will remove the secondary VE table that is more a hassle to deal with compared to one VE table, that being the primary only. This OS in stock form only uses the secondary VE in speed density, so it has less resolution.
    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
    Senior Tuner kingtal0n's Avatar
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    Feb 2017
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    miami
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    you need a log that shows how much timing is being commanded at the crankshaft for any kind of diagnostic using the dyno

    The dynometer is then used to determine whether the peak cylinder pressure point needs to be moved (ign timing) experimentally, by finding best minimum timing that falls within 10% of peak torque or so. Best Minimum Timing BMT


    For example your graph shows best peak torque around 380. It should hold that 380torque all the way to redline if built properly for a peak of 380x7000/5252 = 500rwhp being typical. To use the dynometer properly, timing is swept (increased and decreased experimentally to determine the location of peak cylinder pressure and region) the results will indicate whether there is an issue with VE. An engine only needs three things:
    1. spark (we just went over how to test the influence of spark)
    2. fuel (using the air/fuel ratio) which falls into fairly specific ranges for n/a engines (12.0 to 12.8 is common) and easily determined using wideband sensor and not overly influential at typical ratios (it won't cause the kind of behavior you see on that graph so we can rule this out more or less as a 'problem')

    3. air. The most likely candidate and the only remaining one once timing and fuel is ruled out.
    These are in no order:
    A. degree the camshaft and find out what the lobes are really doing
    B. compression test for healthy engine stats
    C. examine the layout of the induction system and measure pressure drop where applicable

    summary:
    dyno spark sweep to find minimum timing within 10% of peak torque or so
    engine health/maint (air filter, no clog cat, etc..)
    inspection
    degree the cam

    Theres nothing else I can think of that would still generate the torque curve you have, without coming unglued or showing some kind of oscillation. Did you use smoothing:0 to maximize diagnostics? Always smoothing zero for best viewing of the curve behavior. Smoothing is for finished curves only, engine is done and proper just showing it off.