Recommended for high cylinder pressure (turbocharged, supercharged, nitrous). The ignition system market has changed. The new domestic and import engines no longer use a distributor with one coil. Instead, there are multiple coils - one (1) for each cylinder. Some engines even have a coil mounted on the individual spark plugs. CD ignitions use the high voltage "short spark" principle whereas the BOOST-A-SPARK™ incorporates the preferred higher energy "long spark" (2500 microseconds vs. 200 for CD's.