I wonder if someone can help. I have a 2004 WRX and I am looking for some new spark plugs. Scooby World offer the ones I want but in three different gradesL 6, 7 and 8. Which do I need. The current mods on my car are:

Green panel filter.
Cat by pass pipe.
Ninja rear silencer.
Forge dump valve.
255 LPH fuel pump.

Planned mods are:

Sport cat downpipe.
Remap

Any advice or comments are as ever welcome. Cheers. Wilky.

 

7's because the mapper will probably up the boost

 

I agree, use the 7's and gap them to 0.65.