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Thread: Custom OS 3 Bar fuel control questions!

  1. #1

    Default Custom OS 3 Bar fuel control questions!

    I am getting ready to start tuning a 01' C5 with a 346 twin turbo motor. Today I loaded a new custom OS and a stock bin file into the PCM. Tonight I "built" the tune per the tutorial as well as normal adjustments for a modified motor and saved it as a base file.

    My question is regards to the fueling. On a non custom OS NA setup once the VE tables is dialed in, you can use the PE modifier by rpm to control WOT fueling. Right?

    When tuning with the new OS does that that parameter have any control? It seems like the tutorial refers to the {B3647} Open loop AFR as the sole control of power enrichment fueling.

    If I understand it correctly; it seems as if the tutorial takes away most the of the PCM's ability to interfere with a SD tune. Most of my tuning experience has been with systems like GEN7 and FAST where everything is what it is!

    Can someone please elaborate a bit on the fueling procedures?

    Thanks

    Howard

    www.redline-motorsports.net

    1-954-703-5560

    2006 ZO6 895/866 with APS TT
    2010 SSRS Camaro HTR-900TT (798/801)
    2011 HTR-850R Camaro
    2012 ZL1 Auto (10.33@135 MPH) Video Here!

  2. #2
    Lifetime Member eboggs_jkvl's Avatar
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    Get the LTFTs negative. Once you are tuned and happy with the NON-PE, then you can tune the WOT. Negative says you're rich and the PCM is pulling out fuel. It won't add fuel during PE because it thinks the engine is rich.

    COT will splash in fuel so I had to disable the COT or raise it to keep it asleep.

    THose two things will make WOT tuning hell. You simply use the PE table to tune for the A/F you want during WOT runs.

    E

  3. #3

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    My question assumed that the VE table was properly calibrated so the LTRIMS would be on the negative side. Normally when the VE table is correct the PE modifier should be the table to dial in WOT fuel but what happens with the new OS's extra parameters and the mannor in which it is setup? Open loop AFR etc???

    www.redline-motorsports.net

    1-954-703-5560

    2006 ZO6 895/866 with APS TT
    2010 SSRS Camaro HTR-900TT (798/801)
    2011 HTR-850R Camaro
    2012 ZL1 Auto (10.33@135 MPH) Video Here!

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    I disabled PE mode,set up the VE tables and then used the Commanded AFR table to set up the fuelling, as this only goes to 100kpa I enabled PE mode at 105kpa to command a AFR based on RPM.

    Of course this was semi closed loop SD.
    \"You Can Never Have Enough Horsepower\"

  5. #5
    Lifetime Member MN C5's Avatar
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    My question is regards to the fueling. On a non custom OS NA setup once the VE tables is dialed in, you can use the PE modifier by rpm to control WOT fueling. Right?
    Excellent question, it looks like PE isn't avaible untill you've exceeded the MAP values in B3647. Since we aren't asked to disable PE I would assume the commanded AFR table overrides any values in P3618 or ignors them? I've done several of these tunes N/A but haven't scanned WOT to see if the commanded values in B3647 are being effected by PE


    From the Tutorial
    IMPORTANT
    • {B4205} Closed Loop Temp Enable: Set to max setting
    Engine->Fuel->O2->Parameters.
    • {B4108} STFT Idle Enable: Disable
    In EFILive’s 2 and 3-bar Operating Systems, power enrichment (PE) mode can be
    prevented all the way up to full boost. If you are using the {B3647} Open Loop
    AFR calibration as shown above, then there is no need for PE mode below
    100kPa. Above 100kPa, the PCM will continue to command the value in the
    rightmost column of the {B3647}
    Open Loop AFR calibration. You could then have
    PE mode activate at say, 150kPa to command a richer AFR.
    Page 15 has further explanations on how to set up for boosted applications.
    In this table the PCM will average the values between cells, this means in this
    table the commanded AFR between 95kPa and 100kPa will be somewhere
    between 13.8:1 AFR and 12.5:1 AFR (AFR values shown, NOT EQ Ratio).
    support@efilive.com www.efilive.com

  6. #6

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    I guess with a boosted application, under 100 KPA is only half way there so why would you need PE? If you have a car with boost as soon as you drop the throttle to the floor you are going to climb past the 100 KPA mark pretty quick. What controls fuel after 100 KPA to full boost?

    Another question is how do you AutoTune when in boost conditions? I though AT was only good for part throttle conditions.

    www.redline-motorsports.net

    1-954-703-5560

    2006 ZO6 895/866 with APS TT
    2010 SSRS Camaro HTR-900TT (798/801)
    2011 HTR-850R Camaro
    2012 ZL1 Auto (10.33@135 MPH) Video Here!

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    You have multiple ways of getting enrichment with the custom operating systems.

    The method I use ( also the method when designing the add ons for the OS upgrades ) is to use the AFR table for all areas under 100kpa and the pcm will use these values once you are in boost. And then at a certain throttle position and boost level use the PE table.

    So in effect if you have the 100kpa portion of the table set at 12.8:1 then it will use this value for all boost areas before it enters PE mode , so on my car it uses this value for any boost lower than 8 psi , once 8 psi is reached it goes into a slightly richer condition brought on by entering PE mode.
    You can disable PE mode totally if required but I find it just gets that extra bit of contol when I am under high boost situations and want more enrichment .

    basically the pcm looks at that AFR table until PE mode is enacted exactly the same as it did std ( the only difference is now we are not stuck at 14.63 but can custom tailor the afr's depending on manifold vacuum. Once PE mode is enacted it uses that value until it comes out of PE mode.

  8. #8
    Lifetime Member MN C5's Avatar
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    Quote Originally Posted by Redline Motorsports
    I guess with a boosted application, under 100 KPA is only half way there so why would you need PE? If you have a car with boost as soon as you drop the throttle to the floor you are going to climb past the 100 KPA mark pretty quick. What controls fuel after 100 KPA to full boost?

    Another question is how do you AutoTune when in boost conditions? I though AT was only good for part throttle conditions.
    In the custom OS the extended VE boost table A0009 handles fuel after 100kpa.

    I used auto tune without any issues. Bit I was tuning the old fashion way using a 2 bar map and basically remaping my VE. With the new Custom OS I think you can apply the correction factor to the Extended Boost VE table just as you would to the normal VE table.

    I would only use PE for levels beyond the additional boosted VE tabel. I'm running a 2 bar and if I go beyond 14psi then I would use PE. The tables give you a higher level of control than adjusting the PE does. But before EFI Flashscan and HPT PE was the only way to handle it.

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    Quote Originally Posted by MN C5
    Quote Originally Posted by Redline Motorsports
    I guess with a boosted application, under 100 KPA is only half way there so why would you need PE? If you have a car with boost as soon as you drop the throttle to the floor you are going to climb past the 100 KPA mark pretty quick. What controls fuel after 100 KPA to full boost?

    Another question is how do you AutoTune when in boost conditions? I though AT was only good for part throttle conditions.
    In the custom OS the extended VE boost table A0009 handles fuel after 100kpa.

    I used auto tune without any issues. Bit I was tuning the old fashion way using a 2 bar map and basically remaping my VE. With the new Custom OS I think you can apply the correction factor to the Extended Boost VE table just as you would to the normal VE table.
    Correct

  10. #10

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    OK.

    If I set the 100 KPa column in B3647 to 11.8:1 , how do I control fuel on the other side (or boost)? I assume the B3618 PE modifier table only is enabled when in PE mode; what forces the PCM into PE mode and how do I hold it off from enabling?

    Also when autotuning; is there anyway to command a given AFR for the ranges of load covered in A0009? My undertanding is that the VE table is responsible in telling the PCM where the engine moves the most air and is not really controlling fuel.

    The boosted application I am working on builds 12 psi of boost very quickly. I am aiming for a AFR of 11.8:1 and know as soon as I get up to 4-5 psi it needs a 11.8-12.2 AFR quickly. To bad we couldn't get a commanded AFR table for 105 Kpa and up!

    With AutoTuning, I can see where you set up your commanded AFR and log the actual to determine the BEN factor of adjustment needed. How do you autotune over 105 Kpa if you can't command the fuel you want.

    Sorry for the dumb questions but I am close to finally making sense of the autotune and custom OS stuff.

    Thanks

    Howard

    www.redline-motorsports.net

    1-954-703-5560

    2006 ZO6 895/866 with APS TT
    2010 SSRS Camaro HTR-900TT (798/801)
    2011 HTR-850R Camaro
    2012 ZL1 Auto (10.33@135 MPH) Video Here!

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