Are all you guys getting ready to run at bonneville or something??
Here is an excerpt from a web page I have placed below.
"It takes about 12-14,000 volts to initiate the spark across the plug gap. After the initial arc the voltage required to sustain the arc is much less and drops off significantly. So while you may have a manufacturer claimed 60,000 volt racing coil you can't actually get that across the plug. Since the advantage of CDI is the higher coil output, how does that get used. Well, normally it doesn't. The extra power possible in the coil is "Reserve Voltage". As the plugs wear, fouling, plug wires and connections get worse then the required firing voltage may go up 1-5,000 volts. So the "hotter" CDI coil output can help overcome these obstacles and the ignition system will last longer. So, its not that its working better.... but rather lasting longer that makes a hot coil good. The ideal coil output needed for normal applications is about 30,000 volts.
High RPM / High Compression / Racing applications: Newer techniques are being used to increase spark output. Additionally, CDI typically has a very short spark duration near 10-12 microseconds. As discussed you can't push more than about 20,000 volt across the plug without other stange phenomenon happening. If you were to try you would see arcing down the side of the plug, across carbon buildups at the electrode end, out any weak points in the wire insulation, connections, etc... So how do you get a better spark? Newer ignitions (like MSD-5 for example) are outputting a finely controlled multiple spark pattern into the plug. Instead of one big spark a shower of short duration sparks are flooded across the combustion stroke. This makes for a much more efficient burn. Using this technique newer CDI can achieve longer spark duration times (near 250). This is particularly better for starting, lean mixtures (which are hard to ignite), and high compression situations."
How Ignitions Work Covers all types of ignitions and tells you how they work. It just might help you decide what you really need and what is beyond excessive.
