MSD 8970 Three Stage Retard Control Installation - Manual

3-Stage Retard
PN 8970
IMPORTANT: Read the instructions before attempting the installation.
Parts Included:
1 - 3-Stage Retard Control 4 - Mounting Screws
4 - Mounting Grommets 6 - Retard Modules, 2°, 3°, 4°, 3-Zero°
WARNING: During installation disconnect the battery cables. When disconnecting the battery,
always remove the negative cable first and connect it last.
Note: The 3-Stage Retard Control must be used with an MSD Ignition Control.
Note: When the Three Stage Retard Control is installed the ignition timing will retard approximately
4° from its original setting. After installation, the timing should be checked and adjusted
as necessary.
OPERATION
The 3-Stage Retard Control can retard the timing three different times and each with an individual
amount. The three amounts are cumulative and the maximum amount of retard is 25°. Each retard
stage is activated when its corresponding activation wire is removed from ground and the retard will
remain activated until the wire is grounded again.
There is also a Start Retard circuit that
will retard the timing 10° or 25° during
cranking to ease starting on engines with
locked-out timing or crank triggers.
CYLINDER SELECT
T h e 3 - S t a g e R e t a r d C o n t r o l i s
programmed at the factory for 8-cylinder
engines. It can easily be modified for use
on 4 and 6-cylinder engines. The number
of cylinders is selected by cutting the
Cylinder Select Loops as shown in
Figure 1.
MOUNTING
The 3-Stage Retard Control can be mounted under the hood but should
be away from direct engine heat sources. Make sure that the wiring
reaches their connections. Before mounting the control, install the
supplied rubber grommets into the end panels. Then install the sleeve
with the beveled edge facing down (Figure 2).
Use the Control as a template and mark the mounting holes. Use an
1/8” bit to drill the mounting holes.
Figure 2 Installing the
Vibration Mounts.
Figure 1 Selecting the Number of Cylinders.
CYLINDERS CUT LOOPS
8 NONE
6 RED
4 RED AND BLUE
M S D I G N I T I O N
• w w w . m s d i g n i t i o n . c o m • ( 9 1 5 ) 8 5 7 - 5 2 0 0 • FA X ( 9 1 5 ) 8 5 7 - 3 3 4 4