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  1. #1
    New Member
    Join Date
    Jun 2008
    Location
    Mass
    Posts
    9

    Default 1984 Crossfire Modifications - Performance

    I just picked up an 84 with a manual tranny with only 23k miles on it. Anyone have a list of simple mods that can be easily done to get a little more HP?

    Car runs like new, just looking to add a little get up and go.

    Thanks!

  2. #2
    Member CorvetteArchives's Avatar
    Join Date
    Apr 2001
    Location
    Carbon County, PA
    Posts
    594
    Corvette(s)
    1984 Z51 Silver/Gray & as Much SS & CFibre we find

    :G

    Mind you we have no dyno info...just seat of pants :-) We added a Borla exhaust and it made a significant increase. Also a lower thermostat and fan switch helped to make it more consistant at least. We also added a power pulley set that did wonders and its still VERY driveable. No temp probs thanks to before mentioned stuff and generator still works normally.
    We never added a Hypertech chip and wonder if it would do anything...but not enough to spend the $ apparently :-)
    Adjusting the Throttle Position Sensor can help too. Definitely buy the Helm/GM Service Manual...lots of usefull necessary info!

  3. #3
    Member
    Join Date
    Dec 2002
    Location
    covington,tn
    Posts
    185
    Corvette(s)
    71 big block, 84 coupe

    Default

    I changed the fuel pump out to a later year that delivered a bit more fuel pressure. The one in it is suppose to deliver right at what the throttle bodies need, but if you test them they usually fall short of the amount of pressure being delivered even when new. The throttle bodies have a regulator in the first one the fuel line hits, so it will regulate what the throttle body actually sees. Kinda like a air tool that needs 40psi. You dont usually supply it with a compressor that barely supplies 40psi, you supply it with a compressor that delivers much more but then put a regulator in it to set it at exactly 40psi going to your tool. You can also remove a plug (I believe thats how it works) to give you access to the regulator in the first throttle body, that way you can actually adjust it to the exact pressure needed.
    Some people cut a hole in front right under the hole in the air dam mounted under the hood so it can draw cooler air in instead of the hot air from the engine compartment.
    You can port your intake or buy one someone else has already done.
    Since the only one I have done is the fuel pump, can not tell you much on the "how to" on the others. I'll try and check it later and get back. At work right now.

  4. #4
    Member Buccaneer's Avatar
    Join Date
    Jun 2007
    Location
    Gilbert, AZ.
    Posts
    124
    Corvette(s)
    1982 Dark Claret Coupe - 383CI CFI

    Default

    The crossfire motor is rather sensitive to FP and needs 14-15psi to run the way they really should. To achieve that setting, you may have to replace the fuel pump to the 85-87 corvette pump which is a direct replacement.

    The fuel line from the tank goes into the front TB, the front TB is not regulated and is the compansator side. The rear TB is where the FP regulator is located and can be adjusted after a slight mod by removing the blocking plate in the bottom of the regulator. The line coming out of the rear TB is the return side.

    Bang for the buck on a CFI motor is to port the stock manifold, you'll see a marked performance change along with the FP change.

    Stop by the crossfire injection forum: http://www.crossfire.homeip.net/index.php

    There are plenty of CF members there that can give you advice.

  5. #5
    Member LT4man's Avatar
    Join Date
    Jun 2003
    Location
    Chicago
    Posts
    2,378
    Corvette(s)
    96 Collectors Edition LT4

    Default

    I would suggest you introduce yourself in the New Member Introduction Forum!

    We also really enjoy pics! When you get a chance, post some!

    Welcome to CAC! You will find this a very helpful site.

    SAVE THE
    An attendee at all the CruiseFests including the one which never happened.


    Autosig (Shadow) A

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