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Thread: Does this look like a tune for a cam?

  1. #1
    Advanced Tuner
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    Jun 2008
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    Does this look like a tune for a cam?

    I found the original computer for my 2001 Z28 and read it. I'm pretty sure the previous owner had a fairly big cam in it, but it was stock when I got it.

    If this is a tune for a cam would it be a good place to start if I put a cam back in it? Should I change the things changed in the tuned computer? Then fine tune it from there.

    Thanks in advance for any info.

    Tuned PCM
    Attachment 96028

    Tune in use
    Attachment 96029
    Last edited by Jason B; 4 Weeks Ago at 03:33 PM.

  2. #2
    Tuner in Training
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    The "as read" file has been monkeyed with (at a glance - spark, trans, idle, injectors, PE); judging by the IFR (and lack of other changes) it had redrilled injectors in there at one point, if your fueling is correct now they were probably swapped back out

    I would recommend starting with your current tune or a stock file and working from there - none of the changes made in the "as read" file will make for a better starting point (and I wouldn't say it was put together with a great deal of care in the first place)

  3. #3
    Advanced Tuner
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    What do you mean redrilled injectors?

    Maybe it's a nitrous tune, the car had nitrous on it and a bunch of electronics. I bought it as a roller in 2007 and it was one of the fastest street cars in the area a few years earlier until the engine let go. This tune was done by a 'professional' and couldn't have been that bad. I just don't have many details on the set up.

  4. #4
    Tuner in Training
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    Injectors modified for higher flow by redrilling

    Regardless of the combo the tune you pulled was for - cam, spray, otherwise - there's just no real reason to use any portion as a starting point:

    The airflow models are stock (they may have put them back to stock, or may have never tuned them and just fudged IFR to give okay fueling)
    Spark (HO and idle) isn't tuned in any meaningful way
    Injector tables may not reflect the injectors you currently have
    Changes in the transmission tables are anyone's guess

    The remainder of the changes - deleting TM, changing PE, raising idle - are just bog standard changes

    Even if the old tune was perfectly calibrated for the old combo, without knowing what the old combo was and knowing what you put in will most certainly be different, you'll still need to redo all of those tables - unless the new combo is *very* close to whatever the old combo was, the old tune may be no closer to correctly calibrated than stock

  5. #5
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    Well thanks. I'm just curious if nothing else. I never ran the car with it's original PCM. The engine I bought to put in it came with one and I used it.
    It's been in the car 13 years with no problems.