Injector & Mass Air swap w/out a tune?????

Discussion in '94-95 5.0 Tuning' started by 393strokervert, Aug 28, 2009.

  1. 393strokervert Member

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    I currently have 30# injectors & a C&L meter. I need a New Mass Air (probably going with PRO-M). I personally think the 30's are on the small side for my 393 stroker. I would like to upgrade to 36's as I already have a PRO-M 77mm meter cal'd for 36's but I might even go up to 42's & get a new Mass Air.
    my question is, can I swap in the new injectors & Mass Air without getting a tune?
    also, what are you guy's thought's on injectors sizes for my setup?
    any help or suggestions would be great. Thanks, Joe
    P.S. my ECM is from a 94 Cobra & was tuned/chipped (by the shop that built it) for the stroker motor by the previous owner.
    393strokervert, Aug 28, 2009
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  2. final5-0 Mustang Master

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    Without a way to optimize the pcm settings, you have to resort to the cheat
    method devised by aftermarket meter manufactures

    This is where the meter is calibrated for a certain size injector

    What happens is ... as you move farther and farther away from using
    a meter ... caled ... for 19's ... you encounter low pulsewidth driving
    conditions (idle & cruise) which are too fat :(

    Now ... 24's are not too much of an issue
    and
    30's have been known to ... some of the time ... not be too bad

    But ... larger sized inj's such as 36's & 42's and larger will most likely
    cause an issue

    The deal is ......
    At those low pulsewidth conditions, the large inj's are sloppy at the
    threshold of being just above no flow or off condition which is typically
    where you would be at idle and curise :bang:

    Another thing which it just awful about the ... Cheat Method :notnice:

    It throws your load factors W A Y outta whack in the pcm :crazy:
    and
    Load is what the 94-95 pcm's use to administer fuel/spark :)

    And the final bad thing to say about the cheat method

    The meter is what is used to determind load ;)

    therefore

    You wanna have a meter that accurately reports airflow to the pcm :nice:

    Not a meter that cheats the facts or reports a lie to the pcm :eek:

    Grady
    final5-0, Aug 28, 2009
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  3. 393strokervert Member

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    so,what if I get 42's,a matching Pro-m 90 meter & get it dyno tuned. will that be fine??
    393strokervert, Aug 29, 2009
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  4. dls322 New Member

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    Get it tuned. You will be happy you did. Probably will unleash allot of power that was wasted before
    dls322, Aug 29, 2009
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  5. final5-0 Mustang Master

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    Sure

    As long as your tuner knows his stuff :nice:

    I'd get references from 94-95 folk he has tuned to see how pleased
    they are with his handy work ;)

    Very important ... If your guy checks out ....

    D O N' T buy the meter/inj's until you talk to him for his opinion :Word:

    After all ... HE not Me is going to be punching the buttons :rlaugh:

    Grady
    final5-0, Aug 29, 2009
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