the only FSM on my computer is a 2002. my 2003 paperback is at home. the 2002 states for NGK, 1.0-1.1mm (.040-.043in) obviously for the non mazdaspeed. for the mazdaspeed i can't tell you exact, but i remember seeing it around what i stated. following what the non turbo is, i wouldn't go any tighter than .028in and no bigger than .031in. someone correct me if i'm wrong.
i forget what NGK plugs i'm running but they are a 6 heat range. i'm leaving them in there for now, but prolly gonna buy a 7 heat range pretty soon. one reason i havn't is cuz i'm going pretty rich at times and i don't want to foul the plugs. also i discovered while looking at some freezeframe data on a DTC using my scan tool, the non-mazdaspeed ECU has ignition timing set at around 12 degrees advance in boost.... i haven't heard any detonation so i don't think the ECU is pickin any up and pulling that much timing because if it is i should have heard it. although when my turbo spools i can't hear anything anyway.
