MSD 7531 Programmable Digital-7 Plus Installation - Manual (Page 10)

10 INSTALLATION INSTRUCTIONS
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• W W W . M S D P E R F O R M A N C E . C O M • ( 9 1 5 ) 8 5 7 - 5 2 0 0 • F A X ( 9 1 5 ) 8 5 7 - 3 3 4 4
ADVANCE
This is a Gear Shift Advance feature that is designed to advance the timing (or remove any retards)
during a shift to keep the combustion chamber temperatures consistent.
Note: To advance the timing, the crank trigger must be advanced. Therefore, all other timing func-
tions must compensate for this advance.
Gear: Select the number of gears.
DRpm: Program the rpm drop that indicates a gear change from 200-1,500 rpm.
Deg: The amount of timing that is advanced. This is determined by how much
retard is active. You cannot program more advance than the current amount of retard.
Sec: The amount of time that the advance is active. Adjustable in .01 second
increments from 0-1.5 seconds.
Note: The Step Wire Gear Select program overrides the RPM Drop value for shifts.
CYLINDER COUNT
CylCnt: This is the number of cylinders of the engine. Programmable for 4, 6, 8 and Odd fire
6-cylinders (90°/150° only). Once a change has been made, turn the ignition Off and On to
reset.
Tach Trigger: There are two choices for the output of the tach terminal on the end panel of
the ignition or the Gray wire of the 12-pin connector. The output is a 30° duration 12 volt signal
that is compatible with most tachs and data acquisition systems. The default is Trigger which
provides the most accurate signal for rpm sensing components. The Timing program should
only be used when spark timing data is required by an acquisition control or to fire another
ignition.
INDIVIDUAL CYLINDER TIMING
Each cylinder can be retarded up to 10° in 0.1° increments. Adjustments are made through the CylDeg
menu. Default for each cylinder is 0°. A Cam Sync signal for cylinder number one must be incorpo-
rated. The MSD Fiber Optic Pickup, PN 7555, is the easiest or a pickup kit could be fabricated on the
cam gear (MSD Kit PN 2346).
The spark sequence, or firing order needs to be considered when selecting the ICT. You can go through
the Cylinder Numbers and place them with the corresponding position, or go to the Sequence window
and select from the pre-programmed firing orders. This will help by listing the cylinder number next
to the sequence number.
Spark Sequence Program the firing order of your engine, reference only.
Degree Program the amount of retard of each cylinder. These retard
rates are added to any other retards that are active. Max retard is 30°.
Sequence Select a firing order reference:
Program Order Application
1843 18436572 Most GM, Chrysler and AMC V8
1542 15426378 Most Ford V8
1372 13726548 Ford 341/400
1425 142536 Ford V6
1536 153624 Ford, Camaro, Chrysler, AMC V6
1654 165432 Most GM V6
1436 143625 Odd-fire 6-cylinder