hey I recently developed stuttering after 5000 rpm after the elbow on my twin turbo pipe blew off so i pulled out my plugs and they are ngk iridium BKR5EIX-11 so what I'm wondering is could the plugs have failed and caused an overboost which caused the elbow to blow off just wondering if anyone experienced anything like this before also from what i understand now after reading about spark plugs for the skyline is the heat range should be at least 7 but I've found a lot of different info on gap size from .8mm gap to 1.1mm gap is the smaller gap better if you boost over 7 psi because PFR6A-11 are the stock Nissan Skyline GTR plug made by NGK but from alot of other peoples posts they go with plugs at .8mm, any info will be helpful thanks