1 - Midget Ignition
1 - Magnet .250" x .200"
1 - Aluminum Magnet Rivet
1 - Pro-Data+ Disk
WARNING: During installation, disconnect the battery cables. When disconnecting the battery
always remove the Negative cable first and install it last.
Note: Solid Core spark plug wires cannot be used with the Midget Ignition.
The MSD Programmable Midget Ignition is a distributorless ignition system (DIS). It provides
powerful capacitive discharge sparks for complete combustion while providing a variety of
rpm and timing tuning programs. It consists of an Ignition Control, 2-Channel Coil Pack, and
incorporates a waste spark firing design. This means that two cylinders are fired at the same
time, one on the compression stroke and the other on the exhaust stroke. Two magnetic
pickups are used for trigger inputs and two outputs go to the supplied coil pack. The components offer a direct plug-in wiring harness with sealed, locking Deutsch Connectors. A 12
volt battery is required.
The MSD Programmable Midget Ignition Control requires a crank trigger system. MSD supplies two Non-Magnetic Pickups, but due to the variety of engines and applications, a crank
trigger wheel is not offered. Information is supplied on fabricating a crank trigger wheel.
Note: The Midget Ignition must be used on engines equipped with a battery.
The Programmable Midget Ignition uses a high speed RISC microcontroller to control the
ignition’s output while constantly analyzing the various inputs such as supply voltage, trigger
signals and rpm. The high speed controller can make extremely quick compensations to the
timing and rpm limits while maintaining accurate timing signals to within +/- 0.1° and +/- 10
rpm. The circuits and controller of the Ignition have been thoroughly debounced and suppressed to create protection against Electro Magnetic Interference (EMI).
Note: This Ignition can be removed from power and still retain its programmed settings.
CAPACITIVE DISCHARGE
The Midget Ignition features a capacitive discharge ignition design. The majority of stock
and aftermarket ignition systems are inductive ignitions. In an inductive ignition, the coil must
store energy and step up the supplied voltage to maximum strength between each firing. At
higher rpm, since there is less time to charge the coil to full capacity, the secondary voltage falls
short of reaching its maximum energy level which results in a loss of power or a top end miss.
The Midget Ignition features a capacitor which is quickly charged to 490 - 505 volts and
stores this energy until the ignition is triggered. With the CD design, the voltage sent to the
coil is always at maximum power even at high rpm.
The Midget Ignition produces full power multiple sparks for each firing of a plug. The number
of multiple sparks that occur decreases as rpm increases, however the spark series always lasts
for 20° of crankshaft rotation. Above 1,200 rpm there is only one full power spark, for limiting
power drain on the battery. Multiple sparks will not activate unless rpm drops below 500 rpm.
BATTERY
The Midget Ignition Control will operate on any negative ground, 12 volt electrical system.
The Ignition can be used with 16 volt batteries and can withstand a momentary 24 volts in
case of jump starts. The Ignition will deliver full voltage with a supply of 11- 18 volts and will
operate momentarily with a supply voltage as low as 9 Volts.
If your application does not use an alternator, allow at least 17 amp/hour for every half hour
of operation. The Ignition uses about .8 Amps for every 1,000 rpm. If the engine is cranked
with the same battery or other accessories such as an electric fuel or water pump are used,
the amp/hour rating should be higher. Note: The negative battery terminal must be grounded
to the engine case.
COIL PACK
The MSD Programmable Midget Ignition should be used with the PN 8240 matched connector coil pack. For more information on recommended coils, contact our Customer Support
Department at (915) 855-7123.
TACHOMETERS
The Midget Ignition features a Tach Output Wire (Gray) and Black Ground wire. This wire
provides a trigger signal and ground for tachometers. The Tach Output Terminal produces a
12 volt square wave signal with a 30° duty cycle.
SPARK PLUGS AND WIRES
Spark plug wires are very important to the operation of your ignition system. A good quality, helically wound wire and proper routing are required to get the best performance from
your ignition, such as the MSD 8.5mm Super Conductor Wire. Helically wound wires provide
a good path for the spark to follow while keeping Electro Magnetic Interference (EMI) to a
minimum. Excessive EMI, such as the amount that solid core wires produce, may interfere
with the operation of the MSD. Solid Core spark plug wires cannot be used.
PROTECTION
The Programmable Midget Ignition has a built in reverse polarity protection circuit. This will
protect the ignition in the event of wrong connections. It will also shut off for protection from
a surge in power. The ignition will still operate once the surge or polarity is corrected.
LED INDICATOR
There is an LED that monitors the status of the Ignition. The LED will verify trigger inputs and
will flash trouble codes such as a Code 2 for Low Battery supply voltage.
PROGRAMMING OPTIONS
The Programmable Midget Ignition has many features that give you more control over
your timing and rev limits. For more information on programming these features, consult the
supplied Programming Instruction booklet, or see the Help menu in the Pro-Data+ Software.
The Hand Held Programmer (Fig. 1) allows you to select and program the
different features of the Programmable Midget Ignition. The Ignition does
not need to be connected to the programmer in order to operate because
the program values are stored in an erasable memory circuit in the Ignition
Control. The Programmer only needs to be connected when you want to
check or change programs or to monitor different operating parameters.
Figure 1
PRO-DATA+ (INCLUDED)
MSD has a software package for your PC that allows you to create timing and rpm programs
for this ignition. All of the adjustable parameters can be reviewed and set, then uploaded to
the ignition. This software program is included to allow the upload and download of programs
for the Ignition Control as well as monitoring and editing of all the ignition's parameters. It will
work with any PC running Windows 95, 98, NT, ME, 2000 or XP. More information is available
in the Programming instructions. Visit our website to download the current version at www.
msdignition.com.
CYLINDER SELECTION
The Ignition default is for 4-cylinder operation only, using two mag pickups and two Ignition
Coils for waste spark operation.
PROGRAMMING FEATURES
The most current release of the MSD Pro-Data+ software is available which allows transferring all of the menu items and user data to the PC or from the PC to the timing controller
as well as viewing the Alternate and Run Timing curves and the monitored items. Also this
program allows editing the Alternate and Run timing curves on the PC.
the data to be printed out, timing plots and the other data items, from the Graph-View program.
RUN TIMING RETARD CURVE
This is the default timing curve and is active at all times unless the Alternate Timing Curve
is activated. This Curve is adjustable from 800 – 15,000 rpm and is programmable in 0.1°
increments every 100 rpm. The maximum amount of retard is 25°.
ALTERNATE TIMING RETARD CURVE
This feature provides the opportunity to switch to a second timing curve. This Curve will
override the Run Timing curve when the Dark Blue wire is supplied with 12 volts. It will remain
active until the 12 volts are removed (where the Run Curve becomes active again). This Curve
is adjustable from 800 – 15,000 rpm and is programmable in 0.1° increments every 100 rpm.
The maximum amount of retard is 25°.
Note: Both the Run Timing Curve and the Alternate Timing Curve defaults are zero degrees
of retard over the full RPM range.
START RETARD
This program will retard the timing when cranking to ease the load on the starter and flywheel. The retard will activate during cranking and will automatically turn off at 800 rpm. If
the engine drops below 500 rpm, the Start Retard rate will reactivate. The Start Retard has a
default setting of 15°.
An overrev rpm limit can be programmed in 100 rpm increments from 2,000 to 15,000 rpm.
The limiter has a default setting of 9,500 rpm.
IGNITION COMPENSATION
This compensation circuit is designed for MSD’s Crank Trigger Pickups and is automatic.
The circuit compensates for the inherent retard of magnetic pickups creating stable ignition
timing from idle to the maximum engine rpm. This function is automatic and does not require
any adjustments with the MSD pickups. Note: There is an offset of 4° from the input signals
to output signals to produce accurate timing. This must be taken into consideration when
statically setting the timing.
BATTERY MONITOR
This Ignition has a program that monitors the supply voltage of the battery in real time.
There are three different battery types that can be selected to automatically set a low voltage threshold by entering the number of cells that the battery has from six to 12. The battery
choices are Lead Acid, NIMH and NICAD. The default battery specification is a Lead Acid, 12
volt, six cell battery which has a low voltage threshold of 10.8 volts.
An example of some battery specs are:
12 volt Lead-Acid, 6 cell———10.8 volts
16 volt Lead-Acid, 8 cell———14.4 volts
12 volt NICAD,NIMH, 10 cell— 11.64 volts
The battery supply voltage is shown as BatVolts on the monitor.
Battery type is listed as BattType and BattCells displays the number of cells for selecting the
low thresehold.
13.2 volt NICAD,NIMH, 11 cell- 12.8 volts
14.4 volt NICAD,NIMH, 12 cell- 13.97 volts
BATTERY LOW PERCENTAGE MONITOR
This program is useful to see how the battery is holding up throughout a race. If the supply
voltage from the battery drops below the low voltage threshold, this monitor will display the
percentage of time that the voltage is below the recommended spec. This percentage is taken
from the entire time frame that the engine is run until it is shut off. This value will be stored in
the Ignition until the engine is started again. It is shown as %LOW on the monitor.
For example, if a race lasts 20 minutes (from the time the engine is started) and the voltage
dips below the threshold for 2 of those minutes, the %LOW value would be 10%. Note: If the
engine is started again, the program over writes the previous setting.
ALERTS
Alerts are messages that can be allowed to momentarily interrupt the current display screen
on the PN 7550 Monitor. The Alerts menu allows the user to select alert messages to be displayed, even to interrupt other screens, be scrolled through or skipped altogether. The default
of the Alerts/Scan program is set at 0 and will not show any alerts unless configured to show
any alerts. Until the user desires to change this feature to allow the alert mode of operation.
The alert messages at this time are: Low Spark and DisLost. More alert codes can be implemented as this component matures and as warranted by racer feedback.
OUTPUTS
An LED indicator is mounted on the 6214 end panel and can be used to verify trigger input
from mag-pickups. This LED also displays alert codes such as Low Spark code 2 by blinking
when this condition occurs. This alert code will be indicated both on the LED and the 7550
Monitor/Programmer/PC. An error condition of a lost pickup signal will indicate DisLost and
blink a code 3.
Due to the variety of engines and applications, a crank trigger wheel is not offered and must
be fabricated. The brackets for the two pickups must also be made.
The trigger wheel must be 3/8" thick for the MSD magnet to properly fit. The wheel can by
any type of non-magnetic material (aluminum, non-magnetic stainless, etc...) and can be any
diameter over 4”. MSD offers several trigger wheels for V8 applications that may be modified
for certain applications.
A magnet is supplied that must
be installed in the
trigger wheel. This
magnet must be
oriented in one position to produce
the correct trigger
signal for the non
magnetic pickups.
This is detailed in
Figure 2.
Figure 2 Mounting the Magnet in the Trigger Wheel.
1. Place the magnet in the wheel with the hole in the plastic overmolding facing the front of
the motor. The chamfer in the magnet must be positioned next to the hole for the aluminum
rivet.
2. Insert the aluminum rivet. The rivet must be set using a press or a vice with a set of smooth,
parallel jaws (such as the vice on a milling machine).
MOUNTING THE TRIGGER PICKUPS
Since the MSD Programmable Midget Ignition is a two channel, waste spark ignition system
there must be two trigger pickups. Brackets must be fabricated so the pickups are positioned
180° apart. Figure 3 shows two different mounting brackets.
Individual Brackets: Each pickup can be mounted on it’s own individual bracket 180° from
each other. In this configuration both pickups will need to be moved to make timing adjustments.
One Bracket: By using one bracket to position both pickups, timing adjustments will be easier
to set. The bracket will have to be slotted to make timing adjustments and one pickup will be
fixed and the other one will require adjustment slots to index it 180° from the other. Once the two
pickups are indexed correctly the
entire bracket will be able to be
rotated to make timing changes.
This configuration may be harder
to produce but has the advantage
of easier timing adjustments once
the pickups are indexed.
Care will have to be taken to ensure that the pickups remain 180 degrees apart.