[superbeef1000]

Originally Posted by cliffyk Most aftermarlet COPs for the 4.6L 2V, that look like the OEM units (and maybe the OEM COPs too), are manufactured by a company named Micro-Tech. If you examine them side-by-side you can see that the coil housing moldings are identical, right down to the mold separation lines. They are made to the buyer's specifications, but also within the limits of the basic OEM design package; nonetheless they are all basically the same with a voltage capacity of 40 kV to 60 kV. Interestingly, although there are differing materials and design that can be used for the coil core and windings to effect the peak output voltage, there isn't much that can be done to alter the total available energy (in joules). Here's the secondary waveform of a typical, idle speed, sparkplug firing event: The firing event consists of a voltage build-up sufficient to ionise the plug gap, the actual spark which lasts as long as there is sufficient energy to sustain the spark, and then residual oscillations as the remaining energy is dissapated. The voltage required to ionise the gap and sustain the spark is affected by a number of things, but mostly combustion chamber pressure and gap. The higher the pressure, due to higher compression ratios, forced induction, or engine speed, and the wider the gap, the more voltage will be required to fire the plug. On any reasonably "streetable", pump fuel engine, with factory spec plug gaps the maximum voltage required to fire ionise the gap will be no more than 30 kV, typically 20 to 25 kV even at WOT at high speeds--the "burn" voltage will be 6 to 6 kV. This is why the OEM coils are fine for any bolt-on n/a setup, and lower boost f/i applications. When you get beyond there some of the OEM look-alike coils offering 60 kV potential can help things out--however to do it right Sniper has these 80 kV babies... BTW: I am running Accel COPs, got 'em at a swap meet in Daytona as "new, old stock" for $100. They've got about 30k miles on them and work fine--they also had no affect on performance, but they are yellow and look pretty.

wow thats good stuff