MSD 7531 Programmable Digital-7 Plus Installation - Manual (Page 8)

8 INSTALLATION INSTRUCTIONS
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added together. The maximum retard allowed by the Ignition is a total of 30° (including other
retard amounts from a launch, boost or gear retard).
Activation through RPM: Each step retard can also be activated through rpm. In order to achieve
this, 12 volts must still be applied to the corresponding step retard, and an rpm value must be
selected from the Step RPM menu. When 12 volts are applied, the retard will not activate until
the rpm value is reached. Note that the retard will remain active above this rpm, even when other
stages are activated. It will deactivate when the rpm drops below the set amount.
Note: If you prefer to activate the step retards through the activation wires and not rpm, then the rpm
value in each of the desired step menus must be set to 800 rpm.
Step Retard Off Delay: This feature will set a time based delay to deactivate the step retards.
This is designed to keep the timing retarded to clear the engine of any nitrous oxide prior to
deactivating the retard. It is adjustable from 0 – 2.5 seconds and the default is 0.5 second.
Step Retard Ramp: Each retard step can be ramped to and from its full retard amount over a
time based program (Figure 3). It is adjustable from 0-2.5 seconds in 0.01 second increments.
Default is 0°.
RPM: The minimum engine rpm
that must be reached before a
step retard is activated.
On: The amount of time it takes
for the step retard to reach its
Retard Degree. Allows a gradual
ramp On time to reach the Retard
Degree. User adjustable from
0.00 to 2.50 sec. (0.01 sec
increments).
Off: The amount of time it takes
for the step to retard to reach NO
retard. Allows a gradual ramp Off
time to reach NO Retard. User
adjustable from 0.00 to 2.50 sec.
(0.01 sec increments).
Deg: The amount of retard.
MOMENTARY KILL
This program will provide a way to momentarily
shut off the ignition output. This can be useful
in some applications to stop the ignition output
during a shift. When the Kill circuit is selected
On, the Tan third stage retard activation wire
will be used to kill the ignition output when it
is connected to 12 volts. Once selected as the
Kill program, the Tan wire cannot be used as
a retard step.
Figure 3 Different Retard Activation Options.
TIME
RET
ARD
ON OFF
FULL RETARD
RAMPED
ON
OFF
FULL RETARD
ON RAMPED
OFF
FULL RETARD
On and Off Retard Step, No
Ramping
FULL RETARD
Ramping the Retard On
and Off
Ramping the Retard Off
Ramping the Retard On
RAMPED
ON
RAMPED
OFF