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INSTALLATION INSTRUCTIONS

MSD 6T, 6TN

These Ignitions feature a special 4-wire connector which plugs directly into an external rev limiter; the

MSD

PN 8738 Rev Control or the Soft Touch Engine Control, PN 8968. The PN 8738 is a single rev

limit only, while the PN 8968 features two rev limits and an RPM Activated Switch.

GENERAL INFORMATION

BATTERY

An MSD 6 Series Ignition Control will operate on any negative ground, 12 volt electrical system with

a distributor. The MSD can be used with 16 volt batteries and can withstand a momentary 24 volts in

case of jump starts. The Ignitions will deliver full voltage with a supply of 9 - 18 volts and will operate

with a supply voltage as low as five volts.

If your application does not use an alternator, allow at least 15 amp/hour for every half hour of operation.

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.

COILS

The MSD 6 Series Ignitions can be used with most stock coils and aftermarket coils designed to

replace the stock coils. There are some "race only" coils such as the MSD Pro Power Coil, PN 8201,

that

cannot be used with a 6 Series MSD Ignition Control. For more information on recommended

coils, consult the supplied Coil Application Chart or check with the manufacturer of your coil. If you

have any questions concerning coils, contact our Customer Service Department at (915) 855-7123.

TACHOMETERS

The MSD Ignition features a Tach Output Terminal on the side of the

unit. This terminal provides a trigger signal for tachometers, a shift

light or other add-on rpm activated devices. The Tach Output Terminal

produces a 12 volt square wave signal with a 20% duty cycle.

Some vehicles with factory tachometers may require a Tach Adapter

to operate with the MSD. For more information on Tachometers and

MSD Tach Adapters, see the Tachometer Section on page 7.

If your GM vehicle has an inline filter it may cause the tach to drop to

zero on acceleration. If this occurs, bypass the filter.

FOREIGN VEHICLES

Due to the fuel injection systems, some foreign vehicles may require a

special Tach/Fuel Injection Adapter to use an MSD Ignition. See pages

7 for wiring and Tach Adapter information.

Note: Vehicles originally equipped with a CD ignition control cannot use an MSD.

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 Heli-Core or 8.5mm Super Conductor Wire.

Note: Solid Core spark plug wires cannot be used with an MSD Ignition.

A helically, or spiral wound wire must be used. This style wire provides 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, will interfere with the operation of the MSD.

Figure 1 Tach Terminal