hi,
currently facing some problems with my nosram RS12 sp engine...25%trinity.
engine shimmed correctly for 25%.

engine runs fine when using nosram#7 plug but the plug doesn't lasts!
the plug wire will get broken; compression too high? it's shimmed correctly i'm sure. tuning too lean? temp is about 110degC and smoke is visible when throttle.

tried a couple of nosram#7 plugs and still happens, plug wire broken (tried riching but still happens!)

bought a couple of IDM#6 plugs to try and now the plug stays good, wire looks shiny and wet. but the engine will stall easily...with nosram plug, it'll not stall.

what could be wrong? plug or tuning? maybe both?!

any suggestions?