Spark Plugs

Yes... a page just of plug info!

I am currently running NGK Extended Reach plugs (as sold by Flyin Miata or other local autoparts stores such as Advance Autoparts).  The stock number is: 4291 and the part number is: ZFR6F-11.  I have also heard of others w/ F/I miatas running a "cooler" plug.  The stock number is: 2975 and the part number is: ZFR7F-11.

I have reduced the gap from  the factory spec of 0.044 inch to approx. 0.030 inch on each injector for boost applications.  Flyin Miata suggests this when running over 10psi of boost.

As for plug wires, I'm using Magenecor 8.5mm competition wires.  They seem to be good wires.  NGK makes good wires too.  Avoid the black wires, get the blue ones.  The OEM miata wires are notorious for failing.  Sputtering is supposedly often cured with new wires.