I have a 06 MC-S and the mods i have are
-M7 16% pully w/ gatorback belt
-Alta intake V2
-Msd ignition module with competition plug wires
and well i have a problem i was running stock heat range spark plugs and when running flat out one night my car tunned 18.5 psi and well here is a picture of the plug


now i put in the plugs that came with my msd module they are 1 stage colder and well now it when first started for when cold or just randomly it will die and you have to start it and wants to sputter until its been redlined then runs fine.
I dont know if im the only one to have this problem but seems like the plugs are to cold now and were to hot before im really out of ideas on what to do.

 

Ouch!!! That looks like it hurt... did you check in the cylinder to see if any of that fell in?

what kind of plugs did you put in it? ngk BKR7EIX?

 

the ones that came with my msd are brisk plugs dont know the number right off hand but you can go to altaperformance.com and look at the plugs that 1 stage colder and thats them.

 

I've seen that happen with several sets of Iridium plugs. That's why I only suggest the JCW plugs.

 

You got 18.5 pounds with just a 16%? What was that measured with?

 

I would try to go back to the original OEM ignition set up and install the colder JCW plugs, for starters.

I would also have to think there is debris in the cylynder from that plug.

 

I had something like this happen in 2009. I did a new oem coil pack, new oem wires, and BKR7EIX plugs. Once those 3 ignition system components were replaced and all adaptations cleared the problem went away.