My standard (apart from Mazdaspeed catback and HKS filter in standard box) \'92 J-spec, needs new spark plugs.
And having read this review of spark plugs for the FD:
http://www.silverbulletrx7.com/plugs/index.html
along with the *** Spark Plug Q\'s & A\'s for the FD RX-7 *** thread at http://www.mazdarotaryclub.com/forums/showthread.php?s=&threadid=264
I decided to try Brisk DOR14LGS leading (14 being equivalent to heat range of 7.5) and D0R10LGS trailing (9.5 equiv). These incidentally cost £36.50 inc. delivery from Canada, and delivery itself took 2 weeks: very reasonable.
Although the electrode of a Brisk DOR10LGS plug protrudes about 1.5 mm more than a standard NGK plug does, this still leaves enough clearance. The problem is that having received the plugs, I found that the electrode of the hotter DOR14LGS protrudes 1.5 mm more than the DOR10LGS, i.e. about 3 mm more than standard - see attached image...
It\'s only the shorter, colder DOR10LGS that I have found reference to anyone fitting to an RX7.
Has anyone fitted these plugs or know whether there will be enough clearance for them?