The mid 1980s marked the decline of distributors for new cars.
Coil pack technology was adopted by Buick grand nationals, while many other GM vehicles utilized dual tower coil packs, often referred to as waste spark systems.
Other manufacturers followed suit.
Common applications also emerged from Mitsubishi and eventually Chrysler systems.
MSD's DIS ignition controls are intended for engines equipped with coil pack and waste spark ignition systems.
The DIS-2 features two channels to fire two coil packs, while the DIS-4 can fire up to four coil packs, including four individual coils.
Each control provides full power capacitive discharge sparks from idle to racing RPM.
Below 3,000 RPM, multiple sparks occur for up to 20 degrees of crankshaft rotation to enhance idle, starting, and throttle response.
Many adjustable features are included through rotary dials, along with over rev and hole shot protection, plus a step retard.
