MALLORY 678

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
UP
MODE
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
+50
7 - RPM SWITCH
RPM
8 - HSA SLOPE
9 - HSA CUT-IN
A - HSA MAX
B - TRIGGER COMP
C - CYLINDER SELECT
HYFIRE 7C
4 STAGE RETARD
MALLORY IGNITION
www.mrgasket.com
DOWN
Push either of these
buttons to change
the value of the
selected mode.
®
1
Additional Functions:
The 678 Controller has two more functions that can make the
ignition installation and setup work better. One of these is the
high-speed advance function. This lets you put small amounts
of timing in the engine after the torque peak to pick up a bit of
horsepower. There are three things that need to be set up for
this: the cut-in RPM (mode 9), the maximum advance (mode A),
and the slope (mode 8). The cut-in RPM is the RPM where you
want the curve to start working. The slope is how much the
timing will advance every 1000 RPM after the cut-in RPM. The
maximum advance is the highest amount of advance you want
the system to reach.
For example, say that your engine has the torque peak at 6500
RPM, and you want to add some timing after this. You might
want to start adding timing after 7000 RPM, so this becomes
your cut-in speed. If you then want 2 degrees additional timing
at 8000 RPM, then the slope would be set for 2 degrees per
1000 RPM. However, let's say that you don't want more than
2 degrees of advance, so you would set the maximum advance
at 2 degrees, See example 6 for more detail.
The other additional function available is trigger compensation, which is set when the mode indicator is "b". This lets you
compensate for the various delays in ignition timing caused by
both electronic and mechanical changes. To set the trigger
compensation, set mode 9 to 5000 RPM, and mode 8 to zero.
What this does is tell the system to start the high-speed
NC
N
NO
RPM2
RET1
RET2
RET3
RET4
advance at 5000 RPM, but with a slope of zero, there should
be no advance. Once the system is set up this way, watch the
timing as the engine revs past 5000 RPM. If the timing does not
stay at a steady value (once the 5000 RPM point is reached)
then adjust the compensation value until it is as flat as possible.
For example, if the timing retards slightly as the RPM goes up,
increase the compensation value. If the timing advances slightly
as the RPM goes up, decrease the compensation value.
NOTE: This function is only valid for RPM above the high-speed
advance cut-in RPM. If you have the high-speed advance cut-in
set above the normal operational range of the motor, the
compensation function does nothing.
Once the compensation is set, then the high-speed advance
settings will be accurate. The factory setting should be correct
for most types of flying magnet type crank trigger systems, and
should not normally need to be adjusted unless you are using a
different trigger type.
Number of Cylinders Selection
The final mode that can be set is mode "C". This allows you to
select 4 through 12 cylinder operation. This ensures that the
RPML and the timing are proper for the engine. Mode 6F is
special - this is for odd-fire V6 engines ONLY! The cylinder
firing spacing should be 45/75 (at the distributor) or 90/150
at the crank.
From Nitrous
Activation Switch
To Ground
COIL
CONTACT
RELAY
COIL
CONTACT
To +12 Volts
To Nitrous System
RELAY—Use a relay if you are
switching more than 3-5 amps.
EXAMPLE 1: Using the RPM switch (Mode 7) to
turn OFF a nitrous system at a
particular RPM.
NC
N
NO
RPM2
RET1
RET2
RET3
RET4
To Ground
To +12 Volts
EXAMPLE 2: Using the RPM switch (Mode 7) to
turn ON a shift light.
2
www.mrgasket.com
MALLORY IGNITION
NC
N
NO
RPM2
RET1
RET2
RET3
RET4
To +12 Volts
EXAMPLE 3: Using the RPM switch to activate
a retard stage at a particular RPM.
NC
N
NO
RPM2
RET1
RET2
RET3
RET4
To clutch pedal or transbrake switch that
supplies +12 volts when active.
EXAMPLE 4: Staging RPM Limiter (Mode 2).
NC
N
NO
RPM2
RET1
RET2
RET3
RET4
To nitrous stage 1 (+12 volts when active)
To nitrous stage 2 (+12 volts when active, overrides RET1)
To nitrous stage 3 (+12 volts when active, overrides RET1, RET2)
To nitrous stage 4 (+12 volts when active, overrides RET1, RET2, RET3)
EXAMPLE 5: Using the high-speed timing retard
function with a 3-stage nitrous system.
MALLORY IGNITION
www.mrgasket.com
3
CUT-IN (Mode 9)
SLOPE (Mode 8)
MAXIMUM ADVANCE (Mode A)
This is the RPM where the timing
This is how much the timing advances for
This example shows a maximum of 2
starts to advance. This example
every 1000 RPM. This example shows a
degrees advance.
shows a cut-in of 7.0 (7000 RPM).
slope of 2.0 (2 degrees per 1000 RPM).
ADVANCE
8
6
4
2
0
0
2000
4000
6000
8000
10k
EXAMPLE 6: High Speed Advance Curve
(Modes 8 and 9).
MALLORY IS A DIVISION OF THE MR. GASKET PERFORMANCE GROUP
10601 MEMPHIS AVE. #12, CLEVELAND, OH 44144
216.688.8300
FAX 216.688.8306
4
FORM 1520
(REV. B) 09/03
Made in U.S.A.
Printed in U.S.A.
www.mrgasket.com