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An exotic ignition system that can:
- Vary spark energy (1 amp to 100 amps)
- Real time individual cylinder knock detection (every cylinder every time)
- Real time individual cylinder misfire detection (every cylinder every time)
- Operate one to twelve cylinders
- Log or display combustion information on your PC
- Provide individual cylinder timing offsets
The theory is split into two sections. One is the Ignition process, and the other is the Combustion Feedback process.
A spark is formed by discharging a 600 volt capacitor into a coil primary. The coil steps this voltage up to several thousand volts within 1 uS. This causes the spark to jump the gap, similar to a typical CD ignition. The spark reaches 1 amp and then decays for approx 40 microseconds. Additional current can be achieved by previously biasing the extra capacitor, located inside each coil's secondary. If this extra capacitor is not biased, then the CD ignition is not disturbed. If this extra capacitor is biased, then the added energy will discharge into the spark gap. This discharge will occur as soon as the spark is created. Since this energy delivery does not have to go through the ignition coil it delivers up to 100 amps to the spark gap, only for a couple microseconds. Therefore the remaining 38 microseconds only consist of the 1 amp decay.
Combustion feedback is achieved by measuring the conductivity of the sparkgap AFTER the spark extingushes. This conductivity is due to combustion by-products (ions). Just after the spark extinguishes, the extra capacitor is biased with a few hundred volts and if combustion ions are present, a trickle current occurs. Combustion varies this trickle current into unique signatures similar to a heartbeat measured by an EKG machine. A Digital Signal Processor analyzes the signature to extract knock and misfire information.
- 1 to 12 cylinders
- Coil on plug (pencil coil)
- Gasoline, CNG, Propane, Methanol, Ethanol, SI diesel, and various other fuels
- Controllable energy modes (better: cold startablily, cold start emissions, difficult transients)
- Individual cylinder timing maps
- Ion feedback for insight of how the engine is running.
- Twin spark plug applications
- Misfire prevention (if a misfire is in progress a second spark is applied)
- Knock retard (if knock is detected, that cylinder's timing is temporarily retarded)
- Peak cylinder pressure location (each cylinder's timing is adjusted for MBT)
- Air/fuel ratio optimization (information passed back to your ECU)
We recommend a projected surface gap non resistor sparkplug (diagram A below). This plug takes full advantage of all the SmartFire system benefits (the spark and arc characteristics are matched to the SmartFire circuit). A non resistor J gap spark plug (diagram B below) can be used but the combustion improvement benefits of the plasma arc is not guaranteed. A resistor plug can be used but there is definately no plasma arc, so there is no combustion improvement. A heat range change is not recommended.
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