MSD 6201 Digital Ignition Control 
 
6A Ignition Replaces 6200. The base model multiple sparking, CD ignition The new design 6A ignition incorporating a lower profile housing and a new sealed/locked connector.
 
MSD ignitions systems are multiple sparking, capacitive discharge systems. Unlike standard ignition units which only spark once, MSD high performance ignitions spark multiple times through 20 degree of crankshaft rotation up to 3,000RPM. The multiple sparks ensure complete combustion. After 3,000RPM there is not enough time for the plug to fire more than once so there is only a single spark but this is always a full 45,000 volt spark thanks to the capacitive discharge technology. The Capacitive discharge technology ensures the units deliver this very high voltage at any RPM unlike standard ignition units which have a lower voltage delivery (20,000-30,000 volts) and severe voltage reduction at higher RPM. The MSD high performance ignition units deliver the high voltage constantly due to a special transformer in the units which steps up the voltage from the battery and stores it in a large capacitor until the ignition is triggered. The 6 series ignitions are the most popular capacitive discharge systems in the world. Suitable for use with 4, 6 or 8 cylinder engines with 12-volt negative ground electrical systems. They will accept trigger inputs from breaker points, amplifiers and magnetic pickups. MSD ignition units have the following benefits over a standard ignition: Quick starts, increased power, smooth idle, reduced spark plug fouling and crisp throttle response.