MSD/GM HEI Coils

When forced induction is applied to the combustion chamber of an engine, the resistance across the gap of a spark plug increases.  The greater the amount of boost, the greater the resistance.  There comes a point where the factory coils cannot produce a large enough voltage across the gap of the plugs at the right time to initiate a spark.  A couple solutions to this include narrowing the gap of the plugs (from the factory spec of 0.044" to about 0.030") or modify the ignition system to control stronger coils, or at least a combination of each.  Thanks to several folks on the MiataPower list and in the miata.net forums, we were able to figure out how to get stronger coils running in a miata application.

The links below show the procedures for this modification on miatas I've worked with.  

1991 Miata w/ Link ECU: MSD/GM coil packs

1994 Miata w/ Link ECU: MSD/GM coil packs

Here are is the parts list thanks to those that contributed to this modification: