Mallory Ignition ACCEL DIGITAL NITROUS PROCESSOR 74186 - Manual (Page 4)

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Display Range/Resolution Explanation
NO2 Delay 0 – 20 Seconds
The delay timer is used to delay the nitrous system from
engaging once the arming and triggering thresholds are
met. For example: if the system is armed (12v on the arming
input) and the Micro Switch/TPS and RPM input thresholds
are met, the system will wait for the amount shown in Delay
Time before activating the nitrous system. This delay only
occurs after the initial start of the process. If the Micro
Switch/TPS voltage falls below the set threshold, the nitrous
will shut off, but if it goes back above the set threshold, the
nitrous will start again immediately, with no delay. The
arming input is the reset for this function.
NO2/High Speed Timing Retard
0 – 25 Deg in 1
deg increments
This is the ignition retard setting that is used when the
NO2 is activated. Timing is pulled out to avoid detonation
that can cause engine failure. This feature offers a High
Speed Retard that can also be used to pull timing out when
NO2 is disabled. By applying 12V+ to Pin C Yellow Wire on
the 8 pin connector, the processor will retard the timing by
amount set.
RPM Switch
1000-12700
RPM/100 RPM
When the set RPM is reached, the output wire will be pulled
to ground (5 amps max) PIN G Orange Wire. When the RPM
drops 500 below the RPM switch setting, the switch will be
shut off. This prevents “chattering” when the RPM is not
stable. (Can be used to trigger a shift light, secondary
fuel pump, Data acquisition system, etc.)
Main RPM Limit
1000-12700
RPM/100 RPM
This is a fast-acting pulse-by-pulse RPM limiter. It does not
average the incoming period, so it will be rough when the
engine is unloaded, but will control RPM very accurately.
Auxiliary RPM Limit
(Two Step)
1000-12700
RPM/100 RPM
Activated by applying 12v on the Pin D Green/White wire of
the 4 wire connector marked “AUX” input. Same operation
as the Main RPM Limit. (Used mainly as a 2 Step).
Safety RPM 1000-12700
This is used as a NO2 shutoff RPM set point on deceleration.
(Example: If the NO2 Trigger relay or micro switch fails to
disengage the NO2 after you are off the throttle, the Safety
RPM will shutoff the NO2 once below the set RPM.
PWM frequency 5 – 30 Hz / 1 Hz steps
This function is how often per second the solenoids are
cycled. Lower numbers are easier on the solenoids, but can
result in “shuddering”, especially at lower speeds and low
duty cycles. Higher PWM frequency is better for smooth
delivery, but is much harder on the solenoids.
NOTE: Accel/DFI is not responsible for solenoid damage.
Trigger Volts 0 to 20V /.1 volts
After arming the system, this is used as a “start” input from
a Micro switch – Push Button or TPS.
NOTE: If the value is set to zero, the system will start
delivering nitrous when the arming input and RPM setting
is reached. ( We recommend that you use a Micro switch
with this system)
Number Of Cyl Selection 4, 5,6,8,10,12 Cyl. Pick the number of cylinders for your application.
Fuel/N2O offset 1 to 64 Ms / 1 Ms
This is the amount of time that the system delays the
activation of the N2O solenoid after the fuel solenoid, to
give the fuel a chance to start flowing before the nitrous
hits, thus avoiding a lean spike.
PROGRAMMING USING HANDHELD PROGRAMMER CONT’D