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RClewett RClewett is offline
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Join Date: Apr 2010
Location: California
Posts: 15
I would like to clear up some of the misinformation on this thread. While I agree that support is important with any purchase, it's also important to be able to acquire everything as a system rather than piecemeal.

Pricing in post #4 is overstated at $2200. A complete Electromotive top-of-the-line laptop programmable XDI-2 ignition dual plug system, including crank trigger and spark plug wires, ready to bolt-on and go is $1800. The standard XDi dual plug ignition is $1500. For single plug applications, subtract $300 from either of these kits. Take a look in the catalog under ignition and spark plug wires at CLEWETT ENGINEERING: Peformance and Innovation

Regarding the discussion in post #8, the spark duration on a CD and MSD coil is only about .2 milliseconds. The technology is simple, by charging a capacitor and then throwing everything at the coil to extract a hotter spark. With this they open the spark plug gap, increasing the spark voltage to make the spark as big as possible and insure combustion. This higher voltage stresses all the components of the ignition system. The MSD system provides multiple sparks at low RPM to insure ignition.

The distributorless ignitions, including Electromotive and most new car manufacturers, operate on a different principle. They use an inductive system, meaning that the ignition coils are charged rather than a using a capacitor. This includes most coil on plug systems. The spark produced from the properly charged coil of an Electromotive system is 2 milliseconds, or 10 times that of a CD spark. The long spark is used as a way to insure complete combustion, and on new cars to improve reliability, longevity and reduce emissions.

The comment in post #19 is typically from people who try to use the large spark plug gaps of a CD system with an inductive system or improper spark plugs for the application. The waste spark coils from Electromotive are one of the best available to produce a long hot spark.

Furthermore, another important factor in ignition is timing accuracy. Porsche/Bosch has been using a 60 minus 2 crank trigger for years. Now, almost all auto manufacturers use a high resolution system. The reason for this is accuracy. Most high resolution angle based systems are within .2 degrees under all driving conditions. Distributors and low resolution crank triggers are lucky to be within 5 degrees under all conditions.

These are all considerations which should be examined when purchasing an ignition system.
Old 04-24-2010, 02:44 PM
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