i've driven ignition coils with amplifiers before..... they self-resonate at about 2khz. you could try a 555 driving a power transistor. run the 555 at 2khz. connect the transistor across the primary side of the coil with the coil common grounded. connect a 3 amp fast rectifier from ground to the transistor collector with the cathode going to the collector. set up the 555 so that it's on time is about 10% of the total cycle (10% duty cycle). this will turn the transistor on for 10% of the time. during the on time, the collector is close to ground potential, placing a short across the primary terminals of the coil. when the 555 output goes low, the transistor becomes an open circuit and current flows through the coil building a magnetic field. when the 555 goes high again, the transistor shorts the coil, collapsing the field. the current through the coil (from the collapse of the magnetic field) flows through the diode and a voltage spike is created on the secondary. you should use a heat sink on the transistor, since it's on current will be very high (which is the reason for such a short duty cycle). even better would be a large power MOSFET instead of a bipolar transistor since it doesn't put too much of a load on the 555. i can work up a schematic if you want....