FORM 1520 (REV. B) 09/03
INSTALLATION INSTRUCTIONS
4-STAGE RETARD CONTROL
PART NO. 678
Your Mallory HYFIRE
®
678 Control has a number of built-in
features that make it easier to use. These instructions tell how
to use these built-in features.
First, look at the top of the main unit. You’ll see that there is an
8-pin connector beneath the surface. Supplied in the plastic
bag that came with your HYFIRE
®
is an 8-pin plug that fits this
connector. It has screw clamp terminals that accept up to 14
gauge wire. For best results, use stranded, insulated copper
wire, rather than solid wire. The plug is made so that it will
only fit one way, and has hold-down screws at each end.
The connector and mode descriptions are listed below:
RPM Switch:
The built-in RPM switch can either turn an electrical load off or
on at a selected RPM. See below for more detail.
NC
This is the RPM switch (mode 7) relay contact that is
normally closed. In other words, as long as you haven’t
reached the point where the RPM switch is active, this
contact remains connected to the “common” or “C”
terminal. You would use this connection if, for example,
you wanted to turn something OFF (such as a nitrous
system) when you reached the RPM switch point.
See Example 1.
C
This is the common terminal for the RPM switch (mode7)
relay in the main unit. It is connected to the RPM switch,
where it will switch the accessory connected to the “NC”
terminal OFF, and the accessory connected to the “NO”
terminal ON when the RPM switch value is reached.
The “C” terminal can be used to switch either to power
or ground.
NO
This is the RPM switch (mode 7) relay contact that is
normally open. In other words, as long as you haven’t
reached the point where the RPM switch is active, this
FIGURE 1
contact isn’t connected to the “C” contact. You would use
this contact to turn something ON (such as a shift light or
a retard stage) at a specific RPM. See Example 2 and
Example 3.
RPM Limiters:
The 678 Control has two built-in RPM limiters. Each one has a
range of 1000 to 12,800 RPM in 50 RPM steps. On the main
display, there is a decimal point on the mode digit. When that
decimal point is lit up, the RPM limit is increased by 50 RPM.
RPM1
(Mode 1) This is the RPM limit that is always active
if you haven’t selected any other RPM limit.
RPM2
(Mode 2) This is an auxiliary RPM limiter that is
activated when you apply 12 volts to the “RPM2” terminal on
the top-side connector. This could be a starting line limiter.
When selected, it overrides RPM1 (the main engine protection
RPM limiter). See Example 4.
High Speed Timing Retards:
RET1, RET2, RET3, RET4 (Modes 3, 4, 5, 6) These are all high
speed timing retard functions that are activated by 12 volts on
the appropriate top-side connector terminal. Each higher stage
overrides the lower stages, which means that you set each
stage for exactly the amount of retard you want, rather than
adding up each stage to get the actual retard. See Example 5.
NOTE: When you apply 12 volts to RPM2, RET1, RET2, RET3,
or RET4, the display will switch to show that function. If you
have both an auxiliary RPM limit AND a retard selected, the
display will show the retard value.
See the accompanying illustrations for some examples of how
to use the RPM limiters, the RPM switch, and the timing retard
functions.
P/N 678
MODE
UP
NOTE: If any button is held
down for more than 1/2
second, the displayed value
will change automatically
VALUE
1 - RPML 1
50 RPM
2 - RPML 2
STEPS
3 - RETARD 1
4 - RETARD 2
5 - RETARD 3
6 - RETARD 4
MODE
DOWN
+50
7 - RPM SWITCH
RPM
8 - HSA SLOPE
9 - HSA CUT-IN
A - HSA MAX
B - TRIGGER COMP
C - CYLINDER SELECT
Push either of these
buttons to change
the value of the
selected mode.
HYFIRE 7C
4 STAGE RETARD
MALLORY IGNITION
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®
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