As an example we ll use a drag car with a two step module selec tor plugged into the rpm socket of a 7al 2 ignition.
Msd two step instructions.
By connecting one wire to the line lock circuit one module will be activated during the burnout.
For example you can use a lower rpm module for staging and then automatically switch to a higher rpm module after you release your trans brake or line lock.
It provides the ability to set an rpm limit to be used during the launch of the vehicle through a switch or tied into a line lock device or trans brake.
For extended high rpm operation the blaster hvc pn 8252 or hvc ii pn 8253 are recommended.
Page 1 msd module selectors two step pn 8739 three step pn 8737 parts included.
Do not use solid core spark plug wires with any msd component.
1 parts bag wiring terminals 1 module selector 4 mounting screws note.
This two step module is an add on for the msd digital 6al and its purpose is to stop the 6al from delivering spark to the engine holding it at a specified rpm the two step component is used to hold the engine at a lower rpm to control wheel spin and grip to achieve a shorter launch time.
There is a blue wire coming out of the 2 step that controls when the launch.
Connect the 3 pin harness to the 2 step and connect the black wire to the good engine or chassis ground.
The engine speed tab is similar to springs and weights that would normally be found in a distributor.
There is a useful led built into the digital 2 step.
They require the use of plug in modules which are available separately.
This led will illuminate when 12 volts are applied to the blue wire and the low rpm limit of the 2 step is active.
This helps keep tire temperatures consistent.
Page 7 installation instructions custom 1.
The different rpm modules are activated when 12 volts are applied to a corresponding wire.
These msd 2 step module selectors let you choose from two different rpm limits that can be activated at different times.
Gm performance fans will be geeked to learn about this direct plug in 2 step launch control.
The unit is easy to install with factory style connectors for a splice free installation.
The msd 6al 2 ignition can be used with most stock coils and aftermarket coils designed to replace the stock coils.
The position for 11 900 is reserved for use with msd s power grid.
This tab contains two sub tabs with plots that are similar to msd pn6010 pn6012 ignition controllers.
The digital 2 step control is designed specifically for the msd digital 6al ignition control pn 6425.
Wire the 2 step rev limit and the led will turn off.
Page 2 installation instructions rev limiter step module selector pn 8739 black autotronic controls corporation 1490 henry brennan dr el paso tx 79936 module 2 module 1.
Connect all eight of the 2 pin male connectors from the msd harness into the factory coil connectors.
This install being done is on a 1988 chevy camaro iroc z.
Disconnect the 2 pin connectors from each of the eight ignition coils.
