I am fitting an eight plug head to a four cylinder engine. The current ignition runs two double ended coils in wasted spark mode and the two channels control dwell by monitoring primary current. The primaries are earthed by two igbt's in the ignition box (dyna 2000). I need to add another coil to each channel triggered by the primaries. I have bosch bip373 coil drivers and ixd1604 inverting gate drivers (the signal will need to be inverted). Any ideas how I can connect to another coils primary and get a signal that will control a bip373? When the coil current is interrupted to create the spark there is a 300 volt spike on the primary then oscillating around 30v while the spark is happening before it drops to battery voltage. Is this a use for an optical isolator?