I reviewed several cases and so far all applications have led back to detonation.
One was a NA case where the kid removed the EGR but never tuned it. The computer is set for the up to 10% inert gas and therefore would have led to detonation without a tune.
Two other boosted apps have complained of closed ground straps.
I borrowed this from NGK's site:
Detonation
The spark plug's worst enemy! (Besides fouling)
Can break insulators or break off ground electrodes
Pre-ignition most often leads to detonation
Plug tip temperatures can spike to over 3000°F during the combustion process (in a racing engine)
Most frequently caused by hot spots in the combustion chamber.
Hot spots will allow the air/fuel mixture to pre-ignite. As the piston is being forced upward by mechanical action of the connecting rod, the pre-ignited explosion will try to force the piston downward. If the piston can't go up (because of the force of the premature explosion) and it can't go down (because of the upward mo-tion of the connecting rod), the piston will rattle from side to side. The resulting shock wave causes an audible pinging sound. This is detonation.
Most of the damage than an engine sustains when "detonating" is from excessive heat
The spark plug is damaged by both the elevated temperatures and the accompanying shock wave, or concussion
If you can see damage to the piston tops, you now have stress risers which act as knife edges and will only lead to further detonation.
http://forums.stangnet.com/694778-piston-spark-plug-contact-any-ideas.html
This shows the NGK having an extended Tip… Check your NGK’s against Motorcraft
http://forums.stangnet.com/724198-spark-plug-pics.html