Spark plug failure trying to figure out why

[dsmcrzy]

hey guys I recently got my 420a turbo running. The car was previously ran N/A so it only has a few miles on the turbo. I have only hit roughly 4psi because I am still working on the tune (megasquirt ms3x standalone)

Yesterday morning the car gave me more trouble than usual starting. I didn't think much of it since I still need to play with the IAC settings since the turbo install. Yesterday afternoon leaving work it was a bear until it warmed up and the. Sounded like it was missing on one cylinder. So I pulled the spark plugs and the #4 spark plug's insulator nose was fractured.

I am still running the stock temp range plugs but plan to pick up a set 1 step colder. Could it be the plug got too hot? Or could it be from predetonation?

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[motomattx]

Sometimes spark plugs just fail in that manner, it doesnt look like it is suffering from detonation from what I can SEE of it, but that doesnt say much, replace the plugs with a step colder and try again. If you can get some type of knock control/monitoring it would be the best investment you can make right now. It looks like your running Audi coils? keep in mind that the Audi coils or other brands will have their own ignition advance/retard built into them vs your stock setup, have you taken a timing light and checked your true ignition timing?

 

[dsmcrzy]

Yea running Audi coils.

I have the knock module and sensor wired up just haven't finished the settings on the ecu side. Guess I should really get on that now.

I was going to go one step colder and pull some timing. Running 26 degrees right now in boost.