I'm not sure yet if my plugs are incredibly fouled up, but the car seemed slower. I replaced it about 6,000 miles ago. During those 6,000 miles, I had the Craptech FPR, and many times during start up, my FP is so high that it spews out a lot of black smoke, and the car is getting ready to stall out (not completely stall out) for a few minutes. Then the car somehow regain itself. During boosted, and sometimes non-boosted operations, I've also ran super rich between .98-1.0x. It would actually pass 1 volt. Thanks!!!!!

The car just seems slower now, or maybe it is the fact that I'm gettin use to 5-6 psi :P

I change mine often.....about every 1000-1500 miles. I like to keep good plugs in the car at all times, and they are only like $6 for all four plugs.

about every three weeks. Damn DFI foils them and I havent had time to get the pos on a dyno yet.

Every oil change (3K) or just before a track/autocross event whichever is sooner.

Damn, I'm way overdue then!!!! Plugs for me isn't exactly cheap. I use the 7e-11's and they are about 3.99 a piece. Anyways, thanks for the replies!!!

you can get the 7e's from www.clubplug.net for ~$2.19 each.

if your local shop is charging you $4 a plug, theyre screwing you over, shouldnt be more than 1.50-2 bux a pop

That may also be your problem. 7e-11's are one range colder, so if you're not running high boost, it's not creating enough spark to burn all the deposits off the plug, resulting in them fouling.

Most of the DSM's here that run 7e-11's have a 20g or bigger, or only use them at the track when they are making higher boost. But then again, I'm at 6,000ft in elevation, and that changes everything. But you might want to try regular heat range plugs and see how they do.

What NGK spark plug should I use if I am running 5-10 psi with a hrc stage II and stock internals? What is the exact part #?

Advanced Auto Parts - 1.39 each for the 7e-11's

They wont have them instock but will order them. Just take in the part number and they can usually get them for you in two - three days.

hmm haha I can't even remember the last time I changed them gahaha. I had 7es for awhile then I BROKE them take one out so I put my 6Es back and they've been on every since. I noticed the 6es warmed up quicker and does drive a bit better than the 7es, so if your not running a lotta boost like I am 6es are fine. I do check my plugs often though and they've been coming out greyish silver. SO I'm rich but not that rich hehehe....

I change mine about every 9K miles. If there's carbon buildup, and the plugs are in good shape, just brush off the buildup with a small (toothbrush-like) brush. It will be as good as new. Although, I will put in a fresh set just before a big drag event.

No way, your supposed to change spark plugs? j/k ;-) I change plugs every oil change if I can, I am gonna order a box of them next time, so I dont have to always run out and get them. P.S. on the average car, you dont need to replace them all that often unless you notice them fouling or want to clean the carbon buildup... My exhaust blows wet black shit out of it constantly, expecially durring warmup... If you walk behind the car, your legs will be speckled with black shit.. so seeing that, I figure I should replace the plugs whenever I can...