MALLORY 674

®
OPERATING INSTRUCTIONS
FORM #1492 (REV. B) 9/00
HYFIRE® VIIC CONTROL UNIT
PART NO. 674
RPM Switch:
NOTE: This feature is not available on the HYFIRE ® 667C. The builtin RPM switch can either turn an electrical load off or on at a selected
RPM. See below for more detail.
NC
C
NO
RPM Limiters:
The HYFIRE® 667C has three 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.
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 RPM1 (Mode 1)This is the RPM limit that is always active if you haven’t
where the RPM switch is active, this contact remains connected to
selected any other RPM limit.
the “common” or “C” terminal. You would use this connection if, for
example, you wanted to turn something OFF (such as a nitrous 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.
system) when you reached the RPM switch point. See example 1.
This could be a burnout limiter. When selected, it overrides RPM 1
This is the common terminal for the RPM switch (mode 7) relay in
(the main engine protection RPM limiter). See example 4.
the main unit. It is connected to the RPM switch, where it will switch
the accessory connected to the “NC” terminal OFF, and the acces- RPM3 (Mode 3) This is the other auxiliary RPM limiter. It also is activated
by 12 volts on the “RPM3” terminal on the top-side connector, and
sory connected to the “NO” terminal ON when the RPM switch
overrides both RPM2 and RPM1. Use this limit as a staging (startvalue is reached. The “C” terminal can be used to switch either to
ing line) RPM limiter. See example 5.
power or ground.
This is the RPM switch (mode 7) relay contact that is normally High Speed Timing Retards:
open. In other words, as long as you haven’t reached the point RET1, RET2, RET3 (Modes 4, 5, 6) These are all high-speed timing retard
where the RPM switch is active, this contact isn’t connected to the functions that are activated by 12 volts on the appropriate top-side connector
“C” contact. You would use this contact to turn something ON (such terminal. Each higher stage overrides the lower stages, which means that
as a shift light or an air shifter) at a specific RPM. See example 2 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 6.
and example 3.
NOTE: When you apply 12 volts to RPM2, RPM3, RET1, RET2, or
RET3 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.
Push this button to change the mode.
FIGURE 1
Push either of these buttons to change
the value of the mode.
®
NOTE: If any button is held down for more
than 1/2 second, the displayed value will
change automatically.
1
Additional Functions:
The HYFIRE® 667C 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.
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
For example, say that your engine has the torque peak at 6500 RPM, and function does nothing.
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 Once the compensation is set, then the high speed advance settings will be
degrees additional timing at 8000 RPM, then the slope would be set for 2 accurate. The factory setting should be correct for most types of flying magnet
degrees per 1000 RPM. However, let’s say that you don’t want more than 2 type crank trigger systems, and should not normally need to be adjusted
degrees of advance, so you would set the maximum advance at 2 degrees. unless you are using a different trigger type.
See example 7 for more detail.
Number of cylinders selection
The other additional function available is trigger compensation, which is set The final mode that can be set is mode “C”. This allows you to select 4 through
when the mode indicator is “b”. This lets you compensate for the various 12 cylinder operation. This ensures that the RPML and the timing are proper
delays in ignition timing caused by both electronic and mechanical changes. for the engine. Mode 6F is special—this is for odd-fire V6 engines ONLY! The
To set the trigger compensation, set mode 9 to 5000 RPM, and mode 8 to cylinder firing spacing should be 45/75 (at the distributor) or 90/150 at the
zero. What this does is tell the system to start the high-speed advance at 5000 crank.
RPM, but with a slope of zero, there should be no advance. Once the system
NC
N
NO
RPM2
RPM3
RET1
RET2
RET2
From Nitrous
Activation Switch
To Ground
COIL
CONTACT
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.
(Not available when used with the HYFIRE® 667S)
NC
N
NO
RPM2
RPM3
RET1
RET2
RET2
To Ground
To +12 Volts
EXAMPLE 1: Using the RPM switch (Mode 7) to turn ON a shift light.
(Not available when used with the HYFIRE® 667S)
2
NC
N
NO
RPM2
RPM3
RET1
RET2
RET2
To +12 Volts
EXAMPLE 3: Using the RPM switch to activate a retard stage at a particular RPM.
(Not available when used with the HYFIRE® 667S)
NC
N
NO
RPM2
RPM3
RET1
RET2
RET2
To roll control switch that supplies
+12 volts when active
EXAMPLE 4: Burnout RPM Limiter (Mode 2).
NC
N
NO
RPM2
RPM3
RET1
RET2
RET2
To clutch pedal or transbrake switch
that supplies +12 volts when active
EXAMPLE 5: Staging RPM Limiter.
3
NC
N
NO
RPM2
RPM3
RET1
RET2
RET2
To nitrous stage 1 (+12 volts when active)
To nitrous stage 2 (+12 volts when active)
To nitrous stage 3 (+12 volts when active)
EXAMPLE 6: Using the high-speed timing retard function with a 3-stage nitrous system.
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
This example shows a maximum of 2
starts to advance. This example
for every 1000 RPM. This example shows
degrees advance.
shows a cut-in of 7.0 (7000 RPM).
a slope of 2.0 (2 degrees per 1000 RPM).
ADVANCE
8
6
4
2
0
RPM 0
2000
4000
6000
MALLORY IS A DIVISION OF THE MR. GASKET PERFORMANCE GROUP
550 MALLORY WAY, CARSON CITY, NEVADA 89701
(775) 882-6600
FAX (775) 887-4326
www.mrgasket.com
4
8000
10k
FORM #1492
(REV. B) 9/00
Made in U.S.A.
Printed in U.S.A.