Ok so I just went to NAPA and bought myself some NGK spark plugs (BKR7EIX)...but since I've got them I've heard 2 different stories....One saying Copper plugs are better, and another saying iridium are the best...??? Whats your take on this guys? I want to install these tonight....

 

ooohhh you will hear everything man. Both sides have great areguments. I personally had bad luck with NGK BKR7e. Got Zex pluggs and they are great. One of my buddy had the same exact experience with the same results. So for now +2 Zex pluggs.

Remember Canadian gas isnt the same as americans, so as far as pluggs go, take american opinions with a grain of salt

 

basically they offer the same performance.
copper has very very very slightly better conductivity. but its neglegable.

the difference is basically price and longevity.

Copper is cheap, but dont last as long
Iridium conversely, are pricey, but will last alot longer.

basically thats it

 

i have the ngk iridiun in my car that i got from zzperformance and i like them if napa has the iridium u should go back and get them hope this helps

 

Yeah I bought the Iridium ones

 

sweet playboy hope they work as well as they do for me o and dont gap them some people say to but dont its to small to gap and u might break them

 

if you cant gap iridiums, you shouldnt buy them.
running your car with a new set of plugs...and not gapping them correctly, is no different than running the wrong octane fuel.

not a good idea.

 

should pop my knuckles and get my flame suit on ... damn this thing is chared ... anyway.

The deal is that iridium has a higher resistance to heat which is great by itself especially for drag setups however, to that same great ability once they get hot ... they stay hot and having to have a hotter spark at the same time doesn't help. This is because the very same property that makes them resistant to heat makes them retain heat. So lets say you go on a road course one day and run the car hard, you run the risk of pre-ignition due to the excessive heat built up over time especially in boosted cars.

Copper while less resistant to heat, does not need as hot a spark and has the ability to literally cool off faster, yes spark plugs do have a small window in which they will be allowed to literally cool off namely when they aren't sparking and the chamber isn't igniting a small window but one non the less, allowing the car to run harder longer with a much lower risk of pre-ignition.

In calculations iridium is superior in heat resistance but also pales in comparison to coppers ability to cool off quicker before the next spark and coppers ability to run a cooler spark.

hopefully this thread doesn't end up like the battles of the past ... my head is still ringing from all the arguments

 

they are gaped at 40 and they swear up and down u dont need to i also called them and they told me not to cause they could break and they are gaped for our cars and i believe its true i have had them in my car all summer long and they droped my temps a lot so for the price they work great

 

I got Bosch Platinum 4 plus's and theyre awesome, had them for about a year now.

 

what temps?

 

Ok I installed them, and they didnt come gaped .40 out of the box...but that is what i gaped them at. I can notice a little bit smoother idle and acceleration/deceleration. I'm overall pretty happy....but to top it off I got home today and my CW upper and lower billet grills were in!!! YAA.

 

jjust a qiuk question, what model spark plugs should i use for me cobaltss sc mods are cai only

 

stock

 

I think your stockers can handle the extra 5hp

 

Excellent explaination! I was going to chime in with the exact same comparison. There is also more that goes into it, like the electrical conductivity and thermal conductivity and also the hardness of the metal.


The BKR7EIX plugs come gapped at .030 which is going to be way to small. If you don't have a proper gapping tool to gap them without damaging the plugs then I would just stick with the copper plugs so you can get the correct gap. You can get the BKR7EIX-11 plugs which come gapped at .044. Those plugs are easier to gap since you can gently tap the side/top electrode without having to worry about the electrode, just make sure you don't close the gap too much or you are back in the same problem with the gap being too small again.

 

yeah bit i havent changed them since i got it and it is almost at 23000. i want to know which ones so i can change them when i do the oil change

 

yeah I used to explain it better but then people got confused and thats when the fighting started. So now I keep it simple to avoid that confusion. Copper is better overall.

 

The main reason I use the iridiums is because they actually hold heat. Since I rarely go WOT I like the iridiums to help keep the combustion chamber cleaner. If I was going to be running the car hard all the time I would definately go with the copper plugs.

 

please remember that both plugs offer copper cores.
well some may not.....
but most good plugs will be a copper core with either a nickle tip or a platinum tip or iridium or some combonation of above...
precious metals offer longevity over nickle.....

just make sure heat range is proper for your application.. gapping is proper and the plugs in question have a copper core? nickle tips wear faster..... Platinum and iridium wear slower

 

i was told not to gap my iridiums, and i wanna put them in now, but all i have is a 3.1 pulley running on stock equipment, so can i throw them in? and imma be useing the same plugs for when i get my stuff installed this weekend like, 2.8 pulley and 60# injectors, so i have to gap these bad boys?

 

You can gap iridiums - just use a gapping tool. If you touch the iridium tip you can damage it and the car will run like ****.

 

where do the spark plugs get installed at? this isnt like my 6cyl car

....

 

You have to remove the spark plug cover then pull the coil pack and you will see the spark plug.

 

If your running a stage 2 pulley (3.06) i was under the impression that the stock plug's were fine . Were you having any knock or misses ? I run bkr7e's but i changed them to help with a miss i was getting at idle . Just wondering what others think about colder plug's on a stock stage 2 setup .