What Spark Plugs Should I Use For A Tuned St185?

[sweatyfox]

Hiya, My 1991 Celica GT4 is due a service and I was wondering what spark plugs I should use for best performance? I was thinking of using either platinum or Iridium ones.

Also the car is boosting 17psi so im guessing I should be using a cooler grade of spark plug? can anyone recomend what grade or part number I should be using?

Cheers,

Lawrence

[Sketchy]

Hiya, My 1991 Celica GT4 is due a service and I was wondering what spark plugs I should use for best performance? I was thinking of using either platinum or iridium ones.

Also the car is boosting 17psi so im guessing I should be using a cooler grade of spark plug? can anyone recomend what grade or part number I should be using?

Cheers,

Lawrence

NGK iridiums part number BKR7EIX.

The number in the part number refers to the grade. stock is 6, 7 should be fine for yours.