Another Spark Plug Question

[Galois]

Ok guys, please take it easy on this one, I'm new to all this

I've had a pretty long look through the forums and there seemed to be a lot of dispute when it comes to spark plugs. I've got a stock r34 gtt with cat-back exhaust, what should I be using? I'm not sure what's in there not cos i haven't looked since i bought it (only just read how to), so I'll be having a look this week. There is a miss-fire at idle tho.

So what's the deal? Copper, platinum or iridium? They last different amount of time, right? I'm trying to learn as much as i can at the moment so i don't mind changing the plugs every 5000km with oil (also changing that this week cos, its been almost 7000km and starting to hear a bit of ticking, hoping the change will fix it).

I understand is like this: a certain voltage is sent through the plug, which causes the spark, so smaller gap means the spark happens earlier in the piston cycle (as well as being more consistent as less spark is required). Copper requires less voltage to cause the spark (ie more consistent between cycles?), but due to the properties of copper some of the spark plug is lost during each spark. Platinum and iridium are much harder and thus so they don't erode as quickly. The erosion affects when in the cycle the spark fires because it changes the plug gap.

So, please correct me if this is wrong!! And what do i buy? lol

Thanks in advance

[Galois]

oh shite

moderators please delete this one, it came up heaps of times

[BASHO]

oh shite

moderators please delete this one, it came up heaps of times\

So be nice and put in a link