ARC1-003 Air/fuel Ratio Calibrator
Online data sheet below
Description:
The ARC1-003 Air/fuel Ratio Calibrator provides precise adjustment of air/fuel (A/F) ratio over the upper load range of an internal combustion engine. It is designed specifically for naturally aspirated engines with mild performance enhancements. The ARC1-003 follows the stock fuel curve over the light load range which minimizes adaptation on modern closed loop engine management systems. At higher loads, the fuel curve can be made more rich or lean to optimize engine performance.
The LOW control of the ARC1-003 sets the threshold at which alteration of the fuel curve begins. The HIGH control sets the degree to which the fuel mixture is made more rich or lean. A provision on the ARC1-003 allows the modification to the fuel curve to be dependant on an external control input such as MAP or TPS.
The ARC1 is typically used in conjunction with a precision air/fuel ratio meter such as the Split Second ARM1. The air/fuel ratio meter provides the required information needed to properly set the ARC1 front panel controls.
The ARC1-003 is part of the ARC1 family. Several versions are available which are optimized for different applications. The standard ARC1 provides gain and offset calibration and is well suited for general purpose engine calibration. The ARC1-002 is tailored for engines that have been converted to forced induction. It provides compensation for larger injectors and adjustable enrichment in the boost region.
Features:
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Low control sets modification threshold |
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High control sets degree of rich or lean operation in high load range |
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Optional external control input |
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+5V regulated output available for MAP sensor reference voltage |
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Transient surge and battery reversal protection |
Typical Connection:
Connection with TPS used as a control input:
Front Panel Adjustments:
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LOW The LOW control sets the point at which change to the fuel curve begins to occur. The threshold is based on the voltage on the yellow wire. The threshold point can be varied from 1V to 3V. If the yellow and green wires are tied together, the threshold is based on the input voltage. |
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HIGH The HIGH control adjusts the degree to which the stock fuel curve is made more rich or lean above the threshold point. The amount of change to the fuel mixture is a function of the HIGH setting and how far above the threshold VC (the control voltage on the yellow wire) is. |
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Adjustment Procedure:
Begin with the low and high controls set to the zero position. At these settings, the output voltage matches the input. Use a precision air/fuel ratio meter such as the Split Second ARM1 to monitor the operating fuel mixture.
Adjust the HIGH knob to the plus side to make the top end fuel mixture more rich. Adjust to the minus side to lean out the top end fuel mixture. The amount of change is a function of both the HIGH setting and how far above the threshold VC (the control voltage) is. For a similar amount of top end enrichment, if the threshold is increased, the HIGH setting must also be increased.
The LOW knob can be adjusted in order to change the threshold where change to the fuel mixture begins to occur. If the threshold is moved down, there is a risk of changes being picked up by the ECU and activating adaptation. Adaptation works to reduce the effect of fuel mixture changes made with the ARC1-003. If changes made through the ARC1-003 are negated by the ECU over time, the LOW setting needs to be increased so that the area of the fuel curve that is altered is above the primary adaptation area.
Wire Assignments:
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CONNECT TO
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Battery positive (+12V)
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Red
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Battery negative (chassis ground)
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Black
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MAF/MAP sensor signal output
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Green
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Yellow
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ECU signal input (MAF or MAP input)
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Violet
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Electrical Characteristics:
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PARAMETER
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CONDITIONS
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VC to BATT-
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1
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3
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V
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-20
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+20
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%
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BATT+ to BATT-
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12
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13.5
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16
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V
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SIGI to BATT-
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0
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5
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V
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SIGO to BATT-
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0
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5
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V
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SIGI to BATT-
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100
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k
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SIGO to BATT-
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100
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+5V output
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500
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mA
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BATT+ terminal
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20
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mA
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Mechanical Characteristics:
(dimensions in inches)
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