SmartFire Test Results

SmartFire Background Research

• MIT doctoral research by Stephan Pischinger (funded by Bosch) demonstrated advantages of surface gap spark plug together with a high current discharge
• MIT gas turbine laboratory demonstrated strobe light ignition of HC mixture (photon energy only)
• MIT strobe laboratory pioneered the strobe light circuit

SmartFire ignition system combines:

• CD ignition (short duration high voltage breakdown)
• Strobe light circuit (high current discharge after breakdown)
• Surface gap spark plugs (efficient energy delivery to the fuel/air mixture + large initial flame kernel)

SmartFire System Improves Combustion Stability

• SmartFire spark discharge results in a larger initial flame kernel and faster burn duration:
  • Fast rise time high voltage breakdown discharge
  • Followed by high current arc phase
  • Long duration can be achieved in multi-strike mode
• SmartFire system reduces engine roughness (reduces fluctuations in cylinder pressure and mean effective pressure)
• SmartFire spark discharge increases the probability of igniting very lean air/fuel mixtures
• SmartFire system can be applied to stratified charge GDI engines to improve ignition performance
• Experimentally validated on numerous engines using engine dyno and chassis dyno tests

SmartFire System Detects Individual Cylinder Knock

• Ion current measured at spark gap responds to pressure waves resulting from knock
• Signal magnitude and frequency response are functions of coil & spark plug characteristics and cylinder design
• Especially beneficial on engines where traditional knock detection techniques (such as block mounted transducers) do not work well over the entire operating range
• SmartFire system can be used to control individual cylinder timing control for optimum performance

SmartFire System Detects Individual Cylinder Misfire

• Ion current measured at spark gap is a function of flame front and post flame conductivity
• Normal combustion produces measurable ion current signal
• No combustion (misfire) produces no ion current signal
• SmartFire system can be used for 100% misfire detection (OBD) >>> especially important for 8, 10, 12 cylinder engines

SmartFire System Correlates with A/F Ratio and Torque

• Features of the measured ion current correlate extremely well with key combustion parameters
• Correlation with air/fuel ratio can be used to maintain cylinder-to-cylinder balance eliminating the need for multiple EGO sensors
• Correlation with torque can be used to set operating conditions for maximum efficiency or peak power
• SmartFire system can be used to control individual cylinders for optimum performance