Ever wondered why distributorless ignition systems (DIS) have become so popular? First of all, you have far greater timing accuracy with a digital signal firing each cylinder, which is far better than a distributor with gears, weights, springs, and all that other monkey motion. Then we have the fact that with one coil per cylinder, there is plenty of time to recharge the coil to full strength before it has to fire again. In the old days, one coil with an inductive ignition system took time to reach full capacity. At high rpm, there was no time to saturate the coil, and spark energy fell off. That’s why capacitive discharge (CD) ignitions became popular for race engines operating at very high engine speeds. In a CD system, the capacitor charges up almost instantly and hits the coil with 400 primary volts that saturate the coil very quickly, but the spark duration is very short. An inductive ignition uses 14 volts to saturate the coil, but the spark duration is longer, thereby delivering more spark energy over a longer period of time. That’s why an inductive ignition is better suited to street driving with lower engine speeds. Inductive engines deliver a hotter, longer spark at idle and low speeds, which is really helpful when cruising down the highway in overdrive at 1,800 rpm. The beauty of the DIS is that now an inductive system can operate at very high engine speeds and still deliver a long duration spark to light the mixture because the coil only has to fire 1/8th as many times as the older single-coil systems. Technology is a wonderful thing, isn’t it?