MSD 7531 Programmable Digital-7 Plus Installation - Manual (Page 6)

6 INSTALLATION INSTRUCTIONS
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REV LIMITS
Up to four different rev limits can be programmed in 100 rpm increments.
RevBurn: Burnout Rev Limit. This limit is activated when 12 volts are applied to the Light Blue
wire. It is adjustable from 2,000 to 12,500 rpm. Note that the Slew Rev Limiter is disabled by
the Burnout Limit.
RevLaunch: Launch Rev Limit. This limit is activated when 12 volts are applied to the Dark
Blue wire. It is adjustable from 2,000 to 12,500 rpm.
RevMax: Max Speed Rev Limit. This is the overrev limit and is active whenever the Launch
and BurnOut limits are off.
OutCam: Select either a Cam Sync output or a Rev Limiting output that can be used with
MSD components that use rpm modules for the rev limit, or data acquisition units.
AdjOff: This program enables an automatic compensating rev limiter that will
correct trigger input offsets and variables. It can be turned On or Off.
RPM: Adjustable in 100 rpm increments from 2,000 – 12,500.
Spool-Up: This program gives turbo cars a fourth rev limit to help the engine spool boost
pressure prior to the burnout. It is active when both the Light and Dark Blue wires are applied
to 12 volts at the same time. It is adjustable in 100 rpm increments from 2,000- 12,500. Default
is 3,000 rpm.
Note: See page 15 for information and examples on how to wire the rev limits.
REVLIMIT CURVE
This program allows you to map an rpm limiting curve based on time. It is programmed in graph view
on the Rev Limit chart and is adjustable in 100 rpm increments down to 0.01 seconds for up to 12.5
seconds.
Pt 1: Adjust from the Rev Limit chart of graph view (up to 32 points).
Time .00: Adjust from the Rev Limit chart of graph view.
RPM: Adjust from the Rev Limit chart of graph view.
RPM SLEW
This program provides an rpm limiting function based on a ratio between engine rpm and time. The
result is a programmable rate of acceleration for each gear. You can program the rate at which the
engine accelerates by selecting an rpm per second. If 3,000 rpm is selected, that means the engine
will be limited to 3,000 rpm per second. This is adjustable for each gear.
Gear 1: The RPM Slew rate for each gear. Adjustable from 1-6.
RPMSlew: The rpm amount per second, adjustable from 100 – 9,900 rpm per second in 100
rpm increments. Note that this Slew rate is disabled when the Launch or Burnout rev limits
are active.
Note: The Slew Rev Limiter is not recommended with distributor triggers. A crank trigger should be used.
MARGIN
The Slew Margin is a program to ensure very accurate rev limiting action especially when an en-
gine accelerates quickly. There is a High and Low Margin value that ranges from 100-990 rpm.
The Margins should be programmed close to the Slew depending on the engine’s acceleration