<-- still using 6s.

 

I buy a box or two of BKR7Es at a time... I wasn't really impressed with the iridiums, especially for the price difference. Car runs slightly better with the copper plugs, at the expense of fouling out every three weeks or so.

 

I installed 7s when i bought my car 2 years ago. Haven't fouled any, they're still perfect and doing well. Not sure why you foul them every 3 weeks.

 

It's in the tune, and I haven't had the time to deal with it.

 

You can't spend 30 seconds removing some fuel by hand?

 

never had any ignition issues so i never bothered to pull any, when i was younger i used to replace plugs all the time thinking it would help something, never did **** so now i just leave them alone unless there's a problem. besides, in 6 years i probably put less than 15K on the car.

 

I could, certainly, though it would probably take a bit longer than that. I just haven't gotten to it.

And 3 weeks was probably a bit of an exaggeration- it's not that frequent.

 

how do you know how hot of a plug you can successfully run? I'm getting my box of **** for the dyno ready.

 

You should always run the coldest plug that will not foul up. Running too hot a plug on a performance vehicle (specially boosted) is a sure to cause detonation.

So your question should be "how COLD a plug can I successfully run?" Answer: Since you are going to the dyno I would use NGK BKR7E plugs.


Tony

 

Yeah, left an extrra 8-bkr7e's in the passenger seat.

 

I have always used NGK ZFR7F11 on any mild 20psi and lower builds. The ZFRs are extended tip plugs IIRC.

 

I tried some Denso Iridiums several years ago when I first had this Miata.

I hated em. The car ran worse despite the part counter guy assuring me I'd love em.

I hated even more that I payed $48 for the set.

As with every other car I've owned in between (Integras, Celica, 240) the NGKs always work the best, and are easy on the wallet.

And as said before, you should be changing them often enough to not worry about fouling, or "extended life span." You can really tell a lot about what's going on from your plugs, and it is THE cheapest, most effective tune up you can do.

I'm sure every one of us changes the oil religiously (if not man have I got a rant for you, I don't care what kind of synthetic you run), we should also keep an eye on the plugs.

 

if your car runs worse with new plugs of any type, ur doin it wrong.