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Thread: Good start tune for Radix 2bar and cos3?

  1. #1
    Member Ritch's Avatar
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    Default Good start tune for Radix 2bar and cos3?

    I'm wondering how my tune looks to more experiences eyes.

    I'm just starting to tune the truck now that the Radix Magnacharger is installed. The vehicle is a 1999 Sierra with original PCM. I have it running now using COS3 1250003. The camshaft is a Comp XR275HR and engine is the LM7 5.3L The MAP is new matching Cobalt SS part. There are no other mods except valve springs and full exhaust without cats. My next step is to get the olod LC-1 wideband working and then work on the VE tables. Did I miss anything obvious? This is my first blower/COS tune.

    It was running ok. Last month I did full dual exhaust with headers and now with COS3. Throttle blip bogs from idle. Attached is a short log. I haven't tried it in gear yet.

    Cheers
    Attached Files Attached Files
    ____________________________
    1999 GMC, rcsb, 2wd, 5.3, XR275HR-12
    Radix magnacharger mp112
    Long tubes true duals, $L60E

  2. #2
    Member Ritch's Avatar
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    Runs pretty good now. Except IAC steps sometimes goes to 150 and hangs during throttle blip. Not always.
    Attached Files Attached Files
    ____________________________
    1999 GMC, rcsb, 2wd, 5.3, XR275HR-12
    Radix magnacharger mp112
    Long tubes true duals, $L60E

  3. #3
    Joe (Moderator) joecar's Avatar
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    What are the specs of the cam (in/ex dur, lsa, adv)...?

  4. #4
    Member Ritch's Avatar
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    Thank you for looking. Here are the specs from the cam card.

    Valve timing. Open. Close
    At .006. Int: 28. Btdc. 68. Aboc
    Exh: 73. Bbdc. 25. Atdc
    110 intake center line

    Int. Ext.
    Duration at .050 222 224
    Lobe lift. .3330 .3340
    Lobe seperation 112.0
    ____________________________
    1999 GMC, rcsb, 2wd, 5.3, XR275HR-12
    Radix magnacharger mp112
    Long tubes true duals, $L60E

  5. #5
    Member Ritch's Avatar
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    This cam does have a fair amount of idle lope. I still have lots of work get the idle as smooth as possible in order to reduce the dreaded rotor knock
    ____________________________
    1999 GMC, rcsb, 2wd, 5.3, XR275HR-12
    Radix magnacharger mp112
    Long tubes true duals, $L60E

  6. #6
    Joe (Moderator) joecar's Avatar
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    IAC goes high because PWM calculates airflow too low...

  7. #7
    Member Ritch's Avatar
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    Thank you Joe
    By PWM do you mean Pulse Width Modulation or am I missing the accronym?

    I have the truck idling quite nicely now by moving the desired and parked airflow up a little more to match the calculated air flow rate.

    Now, I am having troubles uploading any files to the forum. When attempting to upload my selected files receive a red exclamation mark beside them. Maybe this is because I have been using an old windows XP laptop. I'm not sure. Maybe it's time to load efilive into a newer device so that I can continue participate in the forum. I will try to figure out what changed in the last week. This machine was my dedicated tuning laptop
    ____________________________
    1999 GMC, rcsb, 2wd, 5.3, XR275HR-12
    Radix magnacharger mp112
    Long tubes true duals, $L60E

  8. #8
    Joe (Moderator) joecar's Avatar
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    Sorry I meant to say PCM but I was typing from my phone.

  9. #9
    Joe (Moderator) joecar's Avatar
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    Post screen shot of upload problem.

  10. #10
    Member Ritch's Avatar
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    Click image for larger version. 

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Views:	251 
Size:	1.06 MB 
ID:	22793


    I use an old XP laptop just for EFILive. I'm not sure what changed. Not a big deal to move it to a different machine to upload things.
    ____________________________
    1999 GMC, rcsb, 2wd, 5.3, XR275HR-12
    Radix magnacharger mp112
    Long tubes true duals, $L60E

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