Multi-Spark Discharge Ignition Systems Explained!
It's easy to understand why you'd purchase a new ignition system when the one on your truck isn't working correctly-after all, that's what fires the engine! The reasons for replacing an ignition system on a later-model vehicle that seems to work just fine haven't always been crystal clear to many. However, after learning more about how an ignition system works, as well as the benefits provided by a multi-spark discharge setup, we were sold. MSD sent us one, along with a new distributor and coil, and we popped it all on a buddy's '94 F-150. What was it that convinced us? Were we happy with the result? Read on for the answer!
Simply put, an ignition system ignites the fuel inside the engine's combustion chamber. When you turn the key in your vehicle, a low-voltage signal is amplified by an ignition module, and transferred to the ignition coil. The coil works with the vehicle's computer to send electricity to the distributor, which in turn dishes out the electricity to the spark plugs. Spark plugs then ignite the fuel within the engine's cylinders, thus moving the pistons.
Conventional ignition systems cause the spark plugs to fire just once during the piston stroke, but multi-spark discharge systems, like the one MSD provided us, are calibrated so that the spark plug fires several times as the piston moves. This helps foster a more efficient combustion of the fuel in the cylinder-a more complete burn.
Additionally, the MSD ignition module we received is capable of providing much hotter sparks-the greatly amplified output is 450 volts to the coil rather than the 14 that most stock modules provide.
What does this all mean?
Well, a multi-spark discharge system will provide easier engine start-up, reduced spark plug fouling, and the increased combustion efficiency means more power and even better gas mileage in many cases. Drag racers love 'em because the hot, multiple sparks lead to quicker ET's on the track.
After getting all of the MSD stuff on the F-150, the owner told us it's never run stronger or more smoothly. Engine power is at an all time high, and we think gas mileage is even a little better.