like raz said GTR plug injectors or 550's. if you get 550 sard's u need to change rewire the plugs to suit a bit of a bitch. i order some GTR injectors silly buggers sent me a set of 480cc nismo's wot a score.
so i got a set of the NGK BKR7E plugs so i've and that's what most people have told me to put in though theres been other workshops that say the 6's will be fine but having a colder plug will give me peace of mind. worst case scenario is blowing holes in your piston with a hotter plug and i dont want that kind of trouble thanx to those that replied..big help cheers.
so im making the upgrade to splitfire coilpacks, within the package it advises u to switch to a colder plug. at the moment its got the recommended iridiums which are 6's i need confirmation on which to go in, since i got a colder set being the 7's