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Thread: Help with MAF tuning 24x converted LT1

  1. #1
    Electronic Ignition!
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    Help with MAF tuning 24x converted LT1

    Hello,
    Hopefully I'm posting in the right place, but I have 1995 Corvette converted to 24x/411pcm with Torqhead and am trying to learn to tune it. Have already got the idle speeds and trans shift points close to where I want them and am now moving onto the MAF. I've used Trimalyzer and csv format data logs to tune the VE table on my TBI truck but am having trouble getting it to output the correct information to change the MAF values for the Vette. I am making the tune changes in tuner pro and data logging with universal patcher.
    Am I doing something wrong here? Any tips or links to guides on how to do this?
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    Last edited by Cadmaro; 09-16-2023 at 09:45 PM.

  2. #2
    Electronic Ignition!
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    Here is most of my last log file. had to trim a bit to meet the size requirements so hopefully I didn't ruin it.
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  3. #3
    Fuel Injected!
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    Trimalyzer is great but you'll need to tell it what format your MAF table is actually in for its data to make any sense. I haven't looked at an 0411 so I don't know what sort of MAF table it uses, but on a '95 Corvette's stock PCM I had to create a brand-new MAF table in Trimalyzer that matched the Hz values found in the factory BIN, at which point it was able to offer corrections based on my logs. My guess is that's where you're being tripped up.
    1990 Corvette (Manual)
    1994 Corvette (Automatic)
    1995 Corvette (Manual)

  4. #4
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    Quote Originally Posted by NomakeWan View Post
    Trimalyzer is great but you'll need to tell it what format your MAF table is actually in for its data to make any sense. I haven't looked at an 0411 so I don't know what sort of MAF table it uses, but on a '95 Corvette's stock PCM I had to create a brand-new MAF table in Trimalyzer that matched the Hz values found in the factory BIN, at which point it was able to offer corrections based on my logs. My guess is that's where you're being tripped up.
    Maybe I'm not building the table correctly? I made a table with all the correct HZ values but it showed max correction for every value that was logged. I even tried upping the max correction to 100% and then it showed 100% correction for ever Hz the log had any data. Is the a tutorial or write up on building a MAF table somewhere?

  5. #5
    Fuel Injected!
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    Usually seeing max correction means your import settings for the log are wrong. I had that happen when I was importing EEHack logs into it for the first time. Trimalyzer by default uses 0-255 (128 being "no corrections needed") for trim inputs, but EEHack logs use +/- Percentage (0 being "no corrections needed") for trims. What type of trims do your 0411 logs use?
    Last edited by NomakeWan; 09-17-2023 at 06:13 PM.
    1990 Corvette (Manual)
    1994 Corvette (Automatic)
    1995 Corvette (Manual)

  6. #6
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    I changed the settings from 0-255 to match the % in the logs from the 0411. Is it messing up because my logs include both STFT and LTFT from both banks?

  7. #7
    Fuel Injected!
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    Quote Originally Posted by Cadmaro View Post
    I changed the settings from 0-255 to match the % in the logs from the 0411. Is it messing up because my logs include both STFT and LTFT from both banks?
    Nope, I use both banks in my '95 logs as well. Trimalyzer can handle that.

    As a sanity check, make sure that the field mappings are correct as well. If it's pulling data from the wrong field in the log that'll make a mess of things as well.

    EDIT: Just looked at your first post. Looks like you're missing the Integrators. Maybe in your log they're referred to as STFT rather than INT? Either way, you should put STFT into the INT Field Data. Then sanity check and make sure that all the other data that Trimalyzer wants is being pulled from the correct place in your logs.
    1990 Corvette (Manual)
    1994 Corvette (Automatic)
    1995 Corvette (Manual)

  8. #8
    Electronic Ignition!
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    Looks like putting the STFT in the INT fields fixed my issues!
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  9. #9
    Fuel Injected!
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    Heck yeah! Glad you're sorted. Good luck with the tuning work!
    1990 Corvette (Manual)
    1994 Corvette (Automatic)
    1995 Corvette (Manual)

  10. #10
    Fuel Injected!
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    Quote Originally Posted by NomakeWan View Post
    Heck yeah! Glad you're sorted. Good luck with the tuning work!
    With HP Tuners, I have a custom math parameter for fuel trims. I added the Short and Long terms from each bank seperately, divide by 2, then add the total overall trims together and then divide by 2. I usually target trims of -5% to -2%. I always let the PCM pull a bit of fuel.

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