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Thread: "Performance" cam setting = Won't idle lower than 1000rpm when in gear

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  1. #1
    Join Date
    Jun 2015
    Location
    Rochester, NY
    Posts
    11

    Default "Performance" cam setting = Won't idle lower than 1000rpm when in gear

    I have a mopar 440 built to about 500hp. Cam specs are attached below..... I have my system setup for a "performance" cam........

    At startup, seems to take a few minutes for the car to warm up before it won't die out (if I don't feather the gas peddle).

    No matter what I set the target RPM to, when in gear, it idles around 950-1000 rpms..... If in idle, its up around 1300-1400rpm. Fluctuates a bit in idle.... almost as if it races a bit, then backs off.

    Currently the system is NOT controlling timing. When I was on a carb I could idle as low as 600 rpms easily.

    Thoughts? What should I look at? Possible changing the default cam setting off of "Performance"? Mild?

    I can get more info once I get home in regards to what all my settings are at.

    Thanks!
    Phil

    Cam_Specs.jpg

  2. #2
    Join Date
    Jun 2015
    Location
    Rochester, NY
    Posts
    11

    Default

    Um.... according to this:
    cam_duration.JPG

    My "Cam Duration @.050" is 246 degrees.......... which is JUST under the 250 degree limit.

    What would happen if I went to a mild cam setting? Too far out of wack?

    I'll post all of my settings once I get home.

  3. #3
    Join Date
    Jun 2015
    Location
    Rochester, NY
    Posts
    11

    Default

    My current settings:
    Cubic Inches: 446
    # of cylinders: 8
    Camshaft Type: Performance
    Fuel Pump Type: PWM No Regulator
    Air Pump Equipped: No
    IDL RPM Target: 900
    Rev Limit: 6500
    Timing Control: Disabled

    A/F Targets:
    Idle: 13.5
    Cruise: 13.5
    WOT: 12.3
    Nictrous: OFF
    Boost: 11.9

    Timing Disabled

    Pump Squirt: 25%

    Power Valve Enrich: 19%

  4. #4
    Join Date
    Jan 2010
    Location
    Brisbane, Australia
    Posts
    1,412

    Default

    How many steps is the IAC at hot idle?

    Gary
    Regards, Gary

  5. #5
    Join Date
    Jun 2015
    Location
    Rochester, NY
    Posts
    11

    Default

    Hi Gary,
    I'll fire it up tomorrow, get it up to temp...... and check the IAC at hot idle....... Do I check in gear or neutral?
    Phil

  6. #6
    Join Date
    Jan 2010
    Location
    Brisbane, Australia
    Posts
    1,412

    Default

    Hi Phil,
    If the target is 900 rpm, then in neutral I would expect IAC of 5-20.
    Yours sounds like if target is 900, and it's still too fast in gear, IAC is probably at 0.
    Then in neutral with no load, the engine races with the IAC still at 0.
    Close both primary and secondary a fraction at a time until you get the IAC steps into this 5-20 zone.
    I would expect IAC in neutral about 5-20, then in gear could be about 40-50.
    Gary
    Regards, Gary

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