1JZ-GTE Spark PlugsNGK, Denso, OEM Plugs
Twin electrode plugs are recommended due to the Wasted Spark ignition system used on the 1JZ-GTE VVTi engine.
Below are the recommended plugs that many of our own members use and recommend.
OEM: Denso PK20TR11
Recommended: NGK BKR6EK (twin electrode copper plugs ~$8ea) OR Denso PK20TR11 (twin electrode platinum ~$14ea)
Platinum: NGK BKR6EKPB-11 (twin electrode ‘Premium Platinum, Special Design’ spark plugs ~$20ea)
Alternatives: NGK BKR6E, NGK BKR6E-11, NGK BKR7E, or NGK BKR7E-11
Notes: The -11 designation of the above NGK brand spark plugs denotes that the plugs are factory pre-gapped to 1.1mm. The non -11 designated plugs are exactly the same except that they are not factory pre-gapped to 1.1mm, however, I’m jet to find a set of non factory pre-gapped plugs to be anything other than 1.1mm!
SPARK PLUG GAP
The recommended spark plug gap for a stock 1JZ-GTE engine is 1.1mm.
As you increase boost in a BPU application, you should consider progressively reducing the gap on your spark plugs, starting with the largest gap, until such a point that any ignition issues are negated (i.e. misfire, rough idle etc)
Also, before reducing the plug gap too much, consider changing to a colder heat range plug first while starting with the recommended stock 1.1mm plug gap. Only reduce the spark plug gap if problems persist.
SPARK PLUG HEAT RANGE
When increasing boost pressure it is generally recommended to change to a colder range spark plug. In the case of NGK spark plugs, if you were using a heat range 6 plug, you would go to a heat range 7 (colder) plug.
In addition, consider spark plug gap when increasing the performance of your engine as well.
Please note that other spark plug manufacturers may not follow the same heat range numbering system whereby going to a heat range 7 spark plug of another brand could actually increase the heat range.
Notes: Both Champion and Bosch spark plugs use a decreasing value range to indicate colder plugs as opposed to NGK who use an increasing heat range. i.e. When using NGK, a 2 heat range is hotter than a 12 heat range.