Adaptive dwell maintains peak energy throughout the entire RPM range, reducing misfires while improving engine performance.; Develops on average 4 times more available energy between 3000 and 5000 RPM, and 2 times more available plug voltage.; Compensates for inherent electronic delay by adjusting the spark timing throughout the entire RPM range.; Synchronized peak current and spark timing reduces heat build-up.; Senses startup and develops more energy for quicker, easier starting.. PerTronix 92848 Ignitor II Adaptive Dwell Control Bosch 4 cyl. PerTronix 92848 Ignitor II Adaptive Dwell Control Bosch 4 cyl. The Ignitor II has many of the same great features that the Ignitor has, but its smarter. Ignitor II units sense the coil current level and use a powerful micro controller to adjust the dwell. Variable dwell helps to maintain peak energy throughout the entire RPM range. Ignitor II systems develop up to 4 times more energy between 3000 and 5000 RPM than standard ignition systems. High RPM performance is improved when used with the Flame-Thrower II super low resistance (0.6 ohms) 45,000 volt coils.