Pulstar Spark Plugs

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About Electrode Design

For many years, spark plug makers used a large diameter electrode in an attempt to extend the life of their spark plugs. Unfortunately, larger electrodes create a larger surface area where ions can form. Spark creation timing is less consistent because the time it takes to form a condensed amount of ions in one area is random. In an effort to increase spark creation consistency, spark plug manufactures moved to a fine center-wire plug. The smaller diameter surface area allows ions to form in a compressed area, ensuring a more consistent spark formation. But a fine wire center electrode made of copper and other common metals burns too quickly, thus manufacturers started producing the fine wire electrodes with precious metals such as iridium and platinum.

"More recently, spark plugs have been designed with a fine wire tip made of a noble metal (platinum or a platinum alloy) that has significantly improved engine performance and significantly increased spark plug life. The extremely fine wire at the firing tip of the spark plug (generally having a diameter of .025-.035 inches) concentrates the electrical energy used to fire the spark plug, thus increasing spark efficiency. "
- Patent Application, Allied Signal Inc

"Fine wire electrode with an iridium tip (offers) concentrated spark and reduced firing voltage requirements with long wear characteristics... Iridium has a higher melting temperature than platinum, it is six times harder than platinum, and it is more corrosion-resistant than platinum or most other metals."
- What’s New In Spark Plugs, Counterman Magazine

When the piston reaches the optimum point, the ignition coil begins to send electrical current to the spark plug to form a spark. The electrical current attempts to get to ground but cannot because it must first cross the air between the center electrode and ground electrode of the spark plug. Before the energy can cross the spark gap, it must build a bridge of ions in the air between the two electrodes. The ignition coil slowly (relative to the process) increases the voltage until a strong enough electrical field is formed to ionize the spark gap – this is known as spark jump voltage or breakdown voltage. Once the ions become concentrated enough, the energy finally flows across the spark gap, forming the spark.

For many years, spark plug makers used a large diameter electrode in an attempt to extend the life of their spark plugs. Unfortunately, larger electrodes create a larger surface area where ions can form. Spark creation timing is less consistent because the time it takes to form a condensed amount of ions in one area is random.

In an effort to increase spark creation consistency, spark plug manufactures moved to a fine center-wire plug. The smaller diameter surface area allows ions to form in a compressed area, ensuring a more consistent spark formation. As previously mentioned consistent spark creation ensures that the fuel-mixture is ignited at the optimal time; resulting in a smoother idle, quicker throttle response and improved engine performance. According to DENSO®, their fine-wire electrode plug “redefines performance driving with the worlds smallest iridium alloy electrode diameter of 0.4mm” by “[enabling] a high concentration of electrical field which requires lower jump spark voltage. This improves ignition performance, eliminates misfiring and translates into high performance driving. The lower required voltage and high ignitability from the iridium electrode also guarantees smoother idling, improved acceleration and high response driving.”

Pulstar with PlasmaCore plugs are able to take advantage of a larger electrode because our plugs have a capacitor that produces a 5,000,000 watt pulse to pre-sensitize fuel mixture for combustion and produces a spark channel 10 times larger than conventional plugs. These features allow Pulstar pulse plugs to ignite the fuel mixture instantaneously upon spark creation, and burn it more quickly. Pulstar plugs ensure precise combustion no matter the size of the electrode because we can burn more of the fuel consistently, even if it takes longer to ionize the spark gap. Additionally, our large nickel-chromium superalloy electrode extends the life of the plug by slowing electrode wear to preserve your spark gap.

The image below demonstrates how the fine wire electrode ionizes the spark gap quicker than the large diameter electrode by compressing the electrical field. Consistent spark creation is ensured because the ions are forced to form a conductive bridge between the positive and negative electrodes in a condensed area. The fine-wire flame kernel is initiated at a consistent time during each ignition cycle but is rather small in volume. The wide electrode takes longer to create a spark because the ions take longer to form the conductive bridge because of the less concentrated field. The Pulstar with PlasmaCore plug also creates the spark at various times; however the initial flame front is significantly larger and burns the fuel more quickly upon spark creation which results in more consistent and complete ignition. This is made possible by the  fuel-sensitizing plasma field formed by the high energy plasma in the Pulstar PlasmaCore spark. Actual footage of Pulstar’s burn compared to a leading brands premium fine-wire iridium plug was captured by AVL, the world’s largest independent company for the development of powertrain systems with internal combustion engines.

Three-Electrodes