Anybody know what plugs fit that's two or 3 steps colder than stock. NGK is preferred and no iriduim please.

 

LTR7IX-11...2 step colder

check this out

http://www.modernperformance.com/081...c-473_594.html

nvm...those are iridium. just saw that in your post...i fail

 

why no iridium?

 

in my expirience iridiums tend to run hotter, and hold more heat in (negating the some of the benefits of a cold plug) because iridiums usually have a tip with a smaller surface area because iridium is stronger making it not neccassary. further the whole benefit of iridium's is that it last longer before the tip breaks down, but on a real cold plug it will foul out long before the tip breaks down. so it's kind of pointless. also i have found that they tend to be brittle and can break easier under lighter detonation. I'll use it if i have to right now my best choice is the LTR7IX

 

Iridium has a melting point of 4471 degrees.. thats typically not associated with an element that witholds heat. It is a super hard, and yes super-brittle element, but that doesnt mean weak. Are you attempting to angle or align your plugs to squeeze another hp out of em or something? If not, im not sure why you have this notion about iridium being bad or fouling faster, but to each their own. The smaller "tip" also makes the spark more precise with less surface area exposed, not that in this kind of application thats a nescessity or even a measurable benefit.

 

I have never heard of a 3 step colder plug only 2 step... And I've always wondered this but what is the technical reason to run like a 2 step colder plug in the lnf? Would it help at all close to stock? Not meaning to thread jack or anything lol. Also I've never had a problem with the iridiums! I like ngk!

 

just from past expieriences with LS motors both N/A, nitrous, and forced induction. I have seen on at least a dozen occasions cars with iridium be more prone to kr and said kr get fixed by switching to standard plugs of the same heat range. It's not weak at all but from what I seen its more prone to snapping off a ground strap at certain stress points due to brittleness. The whole purpose of irridium is so it lasts a large amount of miles which is great but on a very cold racing style plug it will foul out long before the irridium breaks down. just like any very cold plug will foul out quick.

O yeah they go all the way to 5 steps colder. Im looking for 2 step right now since I have the ZZP kit. 3 step is overkill for 99% of cobalts. thats what I run on my corvette. I'm thinking for the future when it comes to 3 step. The reason you go colder is because the colder you go the more heat the spark plug transfers from the plug to the cylinder head. The hotter the plug the more heat the plug retains. If the plug get's to hot it can act as a glow plug and cause kr. But going colder has a price the colder you go the sooner it will foul out. Iridiums will work fine I just have had better luck with regulars. I'd rather have a 2 step colder iridium than a 1 step colder standard. How I would do an LNF concerning plugs is when you do bolt ons and a tune I would go 1 step colder. when you do a bigger turbo I would go 2 steps colder. And if you get into the engine internals I would go 3 steps colder. You don't want to go too hot though on my corvette we had 1 step colder plugs and we switched to 3 steps colder. by doing that we were able to put 1 more degree of timing and the car picked up 13rwhp.

 

That makes sense, the manufacturing process for irridium is EXTREMELY difficult, its an unbelievable hard element and not easy to work with to mold into shapes and the likes. This means they break it apart (hence the brittleness) and then compress the dust into whatever shape they want. I can see this breaking apart as you mention.
I guess I would still value the iridums improved arc over traditional plugs. but ive never owned a motor that would use such a thing lol.

 

Aren't the stock plugs (ac delco) iridium??

 

^lol, i was just gonna ask that.

 

under typical application sure, when you start tuning to the point where knock becomes a worry, I can definitely see a detonation breaking it apart at the ground strap, as he indicated.

 

yeah guys gm only uses irridium plugs. im not saying irridium is horrible and you shouldn't use it. I would just prefer standard plugs in my application.

 

Ive been running the 3787s which are one step colder for like 4 months now and my car HATES them now. its misfiring like a bitch up top and im gettin sum knock too. Goin back to stock next week. Car liked those

 

Yes they are iridium plugs made by NGK for AC Delco.

 

You are probably going to have to change them a lot more often then the IR plugs. Also. this car is prone to misfires if plug gap and heat range are not perfect.

 

I run LTR6IX plugs, which I believe is ONE step colder and I gap them at .032, this is absolutely the sweet spot for a semi-agressive tune. And/or if you are running a low flow rate water/meth injection. I use the same plug daily driving and on the road course, on a MUCH more aggressive tune, both run with zero knock, the plug itself looks good and seems to be the correct range every time I check it. The ONLY complaint is I lost a slight bit of MPG changing to this plug but not enough to worry about it.

 

yeah I change them every 6 months anyway. Do any of you guys know of any 2 step colder plugs other than LTR7IX

 

None that I ever found to fit ala NGK, sorry. The 6510's (LTR7IX) you list are pre gapped to .044 so it's a challenge to gap them down to .032 and NGK only recommends gapping down .008 from mfg due to alignment issues. Currently running the 6509's (LTR6IX) but like the 3787's better IMO and they come gapped to a tight .032. (Also a HR 6)

Minimal misfires logged with any of the three listed.

 

sorry to thread jack didnt wanna start a whole new thread...wat plug should i run and both heat range and gap..mods are in my sig im currently boosting 14 psi and getting misfire

 

Stock plugs, NGK 5476 and .030 to .032 gap.

 

Replacement oe plugs it is for me but what is part number for them? I may save a few bucks goin outside of dealer. Someone mentioned u can't gap these iridium plugs??!! They come factory at 035. I'm sure they can be gapped to 032 though

 

Just look up the part number for the plugs. I think they are ngk but are made by ac delco. Or just go to dealer and get em. How much u gonna save ordering them online or goin to.a parts store? And don't know if u can gap iridiums? If ur only gapping from 035 to 032 I don't think its a problem but be careful because iridium is very hard and can break. U have a black sedan don't u? I saw u the other day spinning ur wheels at like 50mph, learn to drive bro.

 

I posted what the rebranded stock plugs are above. The stockers have the 5476 stamped right on the metal.

 

Yea that was me... Wasn't I passing u at that moment as u were hitting engine cut? Spinning at 50? Its called a tune, u should get one BRO...

 

i can spin tire at 80 haha just saying bro

P.S i know how to drive my car