MSD 8-PLUS IGNITION CONTROL -- 315-345 mJ per spark, 480 V primary voltage, 50,000 V plus secondary voltage, 20 degree crankshaft rotation spark series duration, 15,000 rpm with 14.4 V rpm range, 12-18 V negative ground voltage required, 36 amps at 12,000 rpm, 4.85 lbs. W, 8.25 x 3.75 x 5.75 in. size; With improved efficiency and internal components; Capable of firing two coils at once for those extreme racers using dual plug race setups.