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Thread: LS1B 1bar SD COS

  1. #1
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    Default LS1B 1bar SD COS

    Is there a COS that only does 1 bar SD? Everything that I can see in the tutorials and online references 2-3 bar. This is for an '02 LS1/A4 car. I tried using the stock OS and failed the MAF, however there have been weird side effects like short shifting the trans a couple hundred rpm at WOT. Figured a COS would correct that, or if there is a better option I am for it.

  2. #2
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    I think I may have figured it out, but want confirmation. It looks on depending on which OS you use will give you different features.
    xxx01 - SD
    xxx02 - SD with valet
    xxx03 - SD, valet, 2/3 bar
    xxx05 - SD, valet, 2/3 bar, tps ve

    Again this is specifically for an LS1B (2002 12212156 OS). In my case I would run a 02020001 OS. This will allow me to run SD with dual spark tables. Also hoping that it will correct the short shift issue AND assume line pressures and A4 functionality will remain the same as if the MAF was functioning. Any input would be appreciated.

  3. #3
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    Honestly right now I don't believe there's any reason to not just go straight to COS5. It has everything the other COS' do and more, so why not just use it?

    It's probably behaving this way because the MAF isn't there, so the TQ calc's are wrong. Switching to a SD OS should correct this, assuming you get your VE+spark dialed.
    ~Erik~
    2013 Sonic RS Manual - 1.4L I4T E78, tuned, turbo mods, etc.
    2008 TrailBlazer SS 3SS AWD Summit White - LS2 E67/T42, bolt ons, suspension, etc.
    2002 Chevy TrailBlazer LT 4X4 Summit White - 4.2L I6 P10, lifted, wheels, etc.

  4. #4
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    The question I have is how does the COS know if you are using 1 bar or 2/3 bar? I dont see any flags/options

  5. #5
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    It doesn't matter, just put "sane" values in the Boost VE table and other COS tables then be on your way. The PCM will simply never get to the crossover point to use the Boost VE table in your case.

    Think of it this way, you can use a COS, but you don't need to use all of the functionality the COS offers. In your case, you just won't use the boost functionality. No need for a flag/config/etc.
    ~Erik~
    2013 Sonic RS Manual - 1.4L I4T E78, tuned, turbo mods, etc.
    2008 TrailBlazer SS 3SS AWD Summit White - LS2 E67/T42, bolt ons, suspension, etc.
    2002 Chevy TrailBlazer LT 4X4 Summit White - 4.2L I6 P10, lifted, wheels, etc.

  6. #6
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    Thanks for that.

  7. #7
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    I have been playing with COS5 running SD, and am having some issues.
    The first is the A0014 table. I was able to get my wot fueling inline at 20C. I then went back out and it was 8C and the wot fueling was off about 3%. As a starting point I used this thread(https://forum.efilive.com/showthread...ur-A0014-s)and the values from post 9 but skewed them so that 1 was at 20C. Based on the description in the table says, the higher the value, the higher the VE value will be (taken from description: But if you entered a multiplier of 1.01 the value will be 3.000 Grams*Kelvin/kPa X 1.01 = 3.030 Grams*Kelvin/kPa.). This is the opposite of how I read that thread.

    The other issue that I noticed is my spark. During wot, my spark is set to 25.5*. At 5000rpm spark is 25* but at 5600 it dips down to 23.5 until 5800, then back up to 24.5 then back down to 24 at 5900. I have no knock, no other tables are influencing the spark(IAT, ECT, EGR etc), and the low octane table is set lower at 22.7*. This happens consistently at the same rpm. A0000 is disabled and a0001/2 are set to 100. Is there anything else that would affect timing?

    Click image for larger version. 

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  8. #8
    Joe (Moderator) joecar's Avatar
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    Can you post your .ctz file here?

  9. #9
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    Here it is.

    LS1B-5.7COS_0006.ctz

  10. #10
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    joe - have you had a chance to review the file?

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