So, I dropped off my car for a Stage 2 install today and wanted GM to throw in the NKG's for me(one step colder) and he was very against it. He said the the stock ones were FAR superior to the plugs I got. I asked him about the car running hotter(bc of the kit and I'm planning a 2.8 pulley) and he said some guy had to TOW his car there and it was ..."found that those plugs were not meant to run with that car ...and the stock ones can handle the new Flash and temps. If this IS true then why is almost everyone running the NGK's at a step colder. This is coming from a certified GM Tech.....so I told him to hold off on putting them in for now til I did more research. Anyone with any legit intel?
Thanks!

 

I don't know about the stock plugs but i've been running those NGK's for a while without issues so I don't know what he is talking about.

 

I got the 2.8 with ngks no problems here and ive had em in for a couple months

 

It just seems that a GM Tech would know his sh*t, but I'm just trying to cover all my bases. Any other GM techs out there on here know anything different? Or anyone alse with any info of suggestions? Also, everyone keeps saying .35 or .40 gap. Anyone split it down the middle and had good or bad experiences?

 

3.15" to 2.8" = .40 Gap
2.7" to 2.5" = .35 Gap

That's it. No need to split it down the middle.

As far as the plugs go. You can get away with the stock plugs. It's just the 1 step colder plugs help with detination under heavy boost at high rpms. That's why they are 1 step colder.

 

I got the Stage II kit and was seeing no knock retard with the stock plugs.

After installing the 2.8" pulley, I was seeing 1-2 degrees of kr at or around 6500 rpms. I installed the NGKs gapped at .037, and the kr went away.

Unless you're planning on dropping down to the 2.8, you really don't need the colder plugs. And if you choose to do so later, a plug change on the Cobalt takes like 15 minutes (which still blows my mind after getting used to 2 hour+ plug changes on my Camaro).

 

Those last two posts were great, thanks! I AM planning on going to the 2.8 as soon as I can get it put on, so I think I will put the NGK's in but not til AFTER I get the 2.8 on. I also take this car to SIR which is 10 min from my house enough to justify the colder plugs. Thanks for the info guys!!!! any other input welcome!

 

I was trying to decide if I wanted to go with the 7's or not too.

I know more money doesn't always equal better but I just feel bad replacing $50 worth the OE platinums with $7 worth the copper plugs.

 

he's wrong plain and simple - put them in yourself

 

I'll put them in myself provided I can hit up my uncle for some tools....IF I decide to put them in...AND if I can find the special "star" tool thingy to get the cover off. Anyone know where to get one?

I'm picking up my car with Stage 2 in it in like 3 hours!!! I'll give you all a heads up on what it feels like and etc...

 

It's a T27 torx which you can get at an auto parts store. Then you need a 10mm and a 5/8" spark plug wrench. Trust me - put them in now

 

dude I was having major issues with the stock plugs. mine were random gaps too likely from being compressed due to added boost and high rpm's and high heat. when I took em out they were **** black with an uber amount of build up like holy **** build up.

Here are a couple pics after I cleaned em up enough so that I could take pics inside cus it is facking HOT OUTSIDE where I had them. They are cleaner than when I showed the guys here at one of our recent meets but you get the idea.

Stock SS/SC plugs