This section will hopefully provide you with some useful information regarding ignition systems, in particular, coil packs. There are some common misconceptions when it comes to this area and most people choose to mask a coil pack problem by altering plug gaps and/or adjusting timing/boost/fuel to 'tune out' the problem.

A coil pack is essentially a voltage 'step-up' device. Much in the same way that a transformer reduces voltage for a given device, a coil pack increases voltage from an input of 5-12V up to an incredible 20,000-100,000V. It does this by way of coil windings on a primary and secondary circuit. The secondary windings are wound around the primary windings and are usually wound a few hundred times more.

Voltage is supplied into the primary circuit. The voltage is broken by way of breaker point or magnetic/optical trigger. The magnetic field of the primary coil collapses rapidly. The secondary coil is engulfed by a powerful and changing magnetic field. This field induces a current in the coils -- a very high-voltage current (up to 100,000 volts) because of the number of coils in the secondary winding. The secondary coil feeds this voltage to the distributor or spark plug via a very well insulated, high-voltage wire.

The ignition system requires resistance to operate effectively. If there is a drop in resistance, the coil pack will not have to work as hard to push out the spark. There are three main areas of resistance in the ignition system, one of which is not part of the ignition system. These are: 1. Ignition lead 2. Spark plug 3. Combustion area

The ignition lead has the least amount of resistance in the circuit but can fail in a number of ways. If the ignition lead has suffered wear or damage, it can produce a massive amount of resistance which, sometimes, can make it impossible for the coil pack to transfer spark to the other end. Remembering that resistance will reduce voltage. Electricity will always take the easiest route so any cracks or damage to the insulation of the lead can cause the spark to exit before it has reached the next greatest point of resistance. The next greatest point of resistance being the spark plug.

Spark plugs are designed to operate in three main ways. Their main function being to deliver spark from the ignition source to the fuel/air mixture. Other functions are to create more resistance so that it induces energy build up in the coil pack, and to remove heat from the combustion chamber into the cooling system. The resistance of the plug is related to the material used in its core and also the gap which the spark has to cross in order to reach the other side. Spark plug gap should not only be analysed according to engine combustion temps and pressure but also to strength of the ignition source. It is best to start with a base of 'factory plug'.

The combustion area is where most people stumble. There is an incredible amount of pressure being produced in the combustion chamber during engine operation. The pressure acts as a resistance to the ignition system. At higher engine revolution and higher power output, the ignition system will require much more voltage to be able to operate efficiently in the new environment. The factory coil packs generally have enough extra oomph to supply a spark intensity of around 25% more (when new). As the coil pack ages, it will diminish this amount until eventually the coil pack will no longer be able to supply enough energy to efficiently operate. Some people refer to boost causing misfire as 'blowing out the spark'. This term is technically INCORRECT as there is no way for the boost to 'blow out' the spark. All valves are closed when spark is delivered so boost pressure in the system has no effect on the spark operation. It is, in fact, the boost pressure's effect on combustion pressure and temperature which makes the misfire occur as the increased combustion pressure and temperature make it much more difficult for the coil pack to operate.

This is where most people fall into a hole. Instead of upgrading the ignition system to the requirements of the new setup...or in some cases just the standard setup, they choose to reduce plug gap (reducing resistance in the plug) or reducing boost (reducing resistance in the combustion chamber). Isn't the whole aim of motorsport to make more hp? You may as well turn everything back to standard and sell your car or trade it for a Corolla. By reducing plug gap, you decrease hp, by decreasing boost you decrease hp. By upgrading your ignition system you CAN run the higher boost, you CAN run the larger spark plug gap. You will make more hp and your engine will be healthier as well.

So next time you have ignition problems...instead of just band-aiding the problem...try fixing it properly. You WILL be amazed at the results