Davis Unified Ignition (D.U.I.) Ford SOS Coils, also known as 'Sultans of Spark', pack advanced technology and electrifying voltage into these small coils to get tire roasting performance out of your late model Ford V8. The SOS coils are designed with increased windings to boost spark output up to 40,000 volts, allowing larger spark plug gaps for more complete fuel mixture for power and fuel economy. Quicker starting, smoother idle and greater throttle response are greatly increased over stock resulting in D.U.I. as the leader in high performance ignition systems. The SOS coils are a direct replacement for the factory coils and do not require any special modifications.