its time for me to replace my spark plugs. the wrx has 66xxx on it . I
found these plugs on scoobytuner and was wondering what everyone else
is using. they are NGK BKR7EIX Iridium Spark Plugs. Any suggestions as
to what brand and material i should use is welcomed. what should the
plug gap be? What does it mean when companies refer to a plug as a step
"colder"? Any advantages with this? Thanks

Do not need a step colder until you have a much bigger turbo. Basically it is how much heat the spark plug can drain out of the cylinder. I would stick with the stock NGK's. NGK BKR6EIX
Plugs should come pre-gapped as they are iridium I would think they should be between .028 and .030.


I would pick these up right here.
http://www.rallysportdirect.com/shop/ngk-wrx-stock-heat-range-spark-plugs-p-2523.html

I've never seen any reason to use the iridiums, they may work better on suby's who knows but the regular NGK's work just fine for me up to 26 psi on my GT30R. Luke is right no reason to go colder until you have a bigger turbo or lots of mods. Really you should stay as warm as you can until you have to drop colder to avoid pre-ignition.

I run a smaller gap when you go with more boost or higher rpm's. But if your running close to stock leave em pre=gapped.

thanks guys. i am running 17psi right now. im sure that is close enough to stock to just leave them pre-gapped. thanks for the link luke. i will probably get them on thursday!

i do know that iridium plugs dont hold up as well as the old electrode's in a higher preformance vehicale. they are not designed for it. id stick with the regular ngk also over the iridium plug. It also doesnt hurt to run a tad cooler plug; it will keep any knock to a minimum (if any).

Stick with the regular old plug thats what i have always ran and never had a problem. i gap all my plugs to .032 and ive never had a problem. but im also only runing 11psi. i also run NGK plugs but i run 2 steps colder. because my vehicle was never equipped with a turbo from the factory.

thanks again with all the input. im sure ill just get the plugs luke put the link for. see how things go from there.

Another one here for stick with the stock NGK.

Just something to think about...... What does you're firing voltage of the spark plug do when you change the material of the plug? It changes also..... And people seam to think that an iridium plug is less apt to foul then a copper or platinum because it is a special magical space age material that was reverse engineered from a UFO crash site. Whatever..... When you step up to a iridium plug in an ignition system that was not designed for it you'll increase the firing voltage the coil has to create to jump the same size gap(due to many variables I'm not going into unless interested). This increases the load on the coil, and the driver circuit. A coil is typically designed to operate in normal conditions at about 25% duty cycle. You change the plug, you change the duty cycle to make up for coil saturation to create the high firing voltage to just the same size gap but different type of plug and you prematurely overheat and damage the coil(s)
Why do those UFO plugs not foul as easy? Higher firing voltage decreases the chance of a secondary miss fire under loaded(stressed) conditions. You can simply achieve the same thing with any other plug by increasing the gap. The only real benefiet would be maintanence interval.

foot tit Just out of curisoty, when you car is tuned via through open source, are you able to change any of the pulse width or sprak dwell timing?

i just usually change my plugs when they fry off and the car starts missin haha