MSD 6421 6AL-2 Ignition Control Box with 2-Step Rev Limiter - Red

The MSD 6421 6AL-2 is the next generation of MSD's legendary 6-Series capacitive discharge ignition controls, combining an all-new cast aluminum housing with advanced digital circuitry for more power and greater reliability. Compatible with 4-, 6-, and 8-cylinder distributor-based ignition systems, this ignition control box connects easily to virtually any 12-volt negative ground distributor system and accepts Hall-effect, magnetic pickup, and points-style triggers.

Key Features:

• Higher spark output — delivers up to 535 volts of primary voltage and 45,000 volts secondary voltage with up to 135 mJ of spark energy per spark
• Multiple spark discharge — fires multiple sparks per cylinder for 20 degrees of crankshaft rotation, ensuring complete combustion for improved power, fuel efficiency, and reduced emissions
• Built-in 2-Step Rev Control — two independent rev limiters managed by an advanced micro-controller; one for high-end overrev protection and a second launch-limit that can be activated via clutch or transbrake switch
• Four rotary dial adjustments — rev limit settings are easily adjusted in 100 RPM increments via four onboard rotary dials — no chips or modules required
• Broad trigger compatibility — accepts Hall-effect sensors, magnetic (mag) pickup, and breaker points triggers
• All-new cast aluminum housing — sleek, durable enclosure with the same proven reliable digital circuitry
• Wide voltage range — operates on 12–18 volts, negative ground

Specifications:

• Current Draw: 0.7 amp per 1,000 RPM
• RPM Range: Up to 12,500 RPM (at 14.4 volts)
• Primary Voltage: 535 V
• Secondary Voltage: 45,000 V
• Spark Energy: 135 mJ per spark
• Spark Series Duration: 20° crankshaft rotation
• Voltage Required: 12–18 V, negative ground
• Color: Red

The MSD 6421 6AL-2 is an ideal performance ignition upgrade for street/strip builds, offering precision launch control and overrev protection in one compact, digitally managed package.