NGK 5238 R5671A-9 3000GT / Stealth Spark Plug Pack of 6

This is a great all around 9 series non projected, non resistor spark plug. This is a great choice for when you are making over 600AWHP on E85 or pushing your gas setup to your limits. It may also help prevent pre-ignition if you do multiple gear long hard pulls. You may find it will foul if you do not run the car hard. Not suitable if you baby the car.

This plug has a good gap for 15 PSI on stock ignition out of the box (not that you'd run 15 PSI with these :)), but you may gap as low as .022 depending on your boost level. We find that .025 - .028 is a great starting point once you get in the high teens to mid twenties boost.

Pack of 6 Spark Plugs

554: Non Resistor
Center Electrode Core Material: Copper Core
Center Electrode Tip Material: Nickel w/ V-groove
Gap Size: 0.020