The module also electronically increases the duration of the spark (dwell), and, in some brands, can be used as a rev limiter. Like the coil, racing modules are made by most ignition manufacturers ...

Moreover, the HEI module's expanding dwell function meant that up to about 3,000 rpm, ... (Mini-VIP), add-on rev-limiter, Performance Distributors indestructible Livewires ignition wires, ...