Wow, I figured the Spark Plug thread would have solved everyones issues and would answer most peoples questions. But now that I read through it the post has too many conflicting solutions. Now even I don't know what to do.

I see get iridium don't get iridium go copper, gap .040 gap .035

And what makes the stock plugs cause problems, the fact that there platinum or the heat range? I see many people say iridium & platinum plugs cause detonation since they stay so hot.

So what is the true detonation problem solver one step colder or copper?

I also see many different numbers used for stock gap settings too, it is .040 not .045 the part number right on the stock plug states that.

 

I'm just as lost as you are dude...In one of my post I was told that my plugs are 2 steps colder...but that was corrected by a pm telling me that they are indeed one step colder. I gapped mine at .40, makes the car smoother with stage 2, and i'm about to add a 2.8 pulley to it. So who knows i'm sure someone will tell me that I am all wrong...

 

NGK BKR7EIX's at .040" working fine here for about a month or so now. No issues.

Had the BKR7E's in at .037" before that. No seat of the pants difference or idling, starting, running etc between the 2 sets.

 

Heat Range


Conversely, a "Cold" spark plug has a shorter insulator nose and absorbs more combustion chamber heat. This heat travels a shorter distance, and allows the plug to operate at a lower internal temperature. A colder heat range can be necessary when an engine is modified for performance, subjected to heavy loads, or it is run at high RPMs for significant periods of time. The higher cylinder pressures developed by high compression, large camshafts, blowers and nitrous oxide, not to mention the RPM ranges we run our engines at while racing, make colder plugs mandatory to eliminate plug overheating and engine damage. The colder type plug removes heat more quickly, and will reduce the chance of pre-ignition/detonation and burn-out of the firing end. (Engine temperatures can affect the spark plug's operating temperature, but not the spark plug's heat range).


C/P from
http://www.centuryperformance.com/sp...#Heat%20Range:

 

It's simple - get copper plugs (BKR7E) and gap them at .035-.040 depending on your pulley size. Really, that's it

 

Stock plug gap is .035 as per SI Doc. #1408393.

 

Do you have a chart that shows gap per the pulley size. I just ordered a 3" pulley but I am stock (PCM, Injectors). I can get the colder plugs but do I gap @ .40 or .35?

 

Here is what I have come up with doing a little research -

for stock to 2.8" pulley .4 is a good gap (you should not gap at the highest tolerance because as the plug gets older the gap will increase)

For 2.7" pulley and lower you should gap at .35

The type of plug will more then likely effect gap also. The more conductive the plug, the wider the gap you can run to ensure better fuel burn. A copper plug could probably be gapped a bit wider then the stock plug because of the better current flow. I would say the iridiums could maybe go only a little wider then the stock plugs due to their slightly better conductivity.

Of course other mods you have done will make a difference in gap as well. The best thing you can do is test gaps for your mods to see which work best.

Anytime you increase horsepower by 50-100 you should also run a colder plug. For our cars the BKR7E and BKR7EIX are both good options. The BKR7E is a copper plug which means you will have to change it ALOT. If you go with the copper plug you will probably need to change it every 10,000 miles.

The iridium plug, which does have a bit hotter tip for the self-cleaning, has better conductivity then the stock platinum plug (though it is alot less conductive then the copper plugs) and should only need to be changed every 50,000 miles or so. The self cleaning should help keep the plug nice and clean though since the cobalt plugs are known to get lots of carbon buildup since they run rich most of the time.

There have been lots of arguments between copper and iridium which led me to do alot of research on them. I have copper BKR7E in my car now and it did help the car run a bit smoother - but I just got my BKR7EIX yesterday and will be putting them in to see how they run and to see how the copper plugs are looking.

 

I pulled my stock ones out and they were at .035" which is what the BKR7E's come gapped at out the box. I'd say use that no matter what pulley size you have down to 2.5". Also, there's no debate that Iridium and Platinum plugs will cause much more detonation because they retain heat too much for FI applications. Also, the BKR7E's are perfect for a bone stock car and work much better than the stock platinum plugs - especially once you start modding. Get the copper plugs and just stick em' in. Everyone keeps making this so hard

 

So why would NGK make a plug for GM that is pre-gapped at .040 if the correct gap is .035?

The NGK OE plugs aren't universal plugs either so it isn't like GM re-gaps them.

 

The gap on my OE plugs matched the BKR7E exactly right out of the box - and I checked every single plug I took out and put in. The stock plugs were about .035 on my guage which, again, was the same as the ones I bought to replace them

 

Are you using a wire gauge or a blade style?

 

When I had the BKR7E's in, they were .037" out of the box on a slider gauge. Like OBSSSD I checked them and just put them in without adjusting the gap.

 

So has anyone ran the BKR7EIX with the out of the box pre-gap setting?

The two I checked were .033, The one I did gap to .040 looked odd since the electrode was so close to the edge of the ground strap.

 

I have seen some people running the BKR7EIX with the out-of-the-box gap. I would not recommend that, as the point in having an iridium plug is to get better conductivity over the stock platinums which means you would get better spark which in turn means you can run a wider gap if necessary.

Also, the iridium plugs do not run overly hot and run twice as cool and have twice the conductivity as the stock platinum plugs do. Copper plugs do run a little more then twice as cool and have about twice the conductivity of iridium. If you are running a 2.8" pulley the iridium should have plenty of spark and should run plenty cool. If you go smaller then a 2.8" pulley you may need all the spark you can get to ignite the fuel under the higher compression and the coppers may work better.

I would like to see a "true" study done to test combustion chamber tempuratures and spark plug tempuratures with different plugs, however I don't see that ever happening.

 

okay after reading this BKR7E's are the best for the stage 2 am i right i know it is not rocket science but people go on staying the 7e's are to go with then they start bring in the IX's saying there is no difference....grrr rnjmur when you put the IX's in did you notice a difference since you were going to research the two plugs.......

 

nobody said there is no difference. if you read carefully the answers are there

 

grrr damn i am a ******* I completely read over matty posts NGK BKR7E are the way to go. lol owell thanks for the input guys

 

I have the BKR7E's back in.
The BKR7IEX's were causing mild detonation.

 

I have the IX plugs in right now, and truthfully I haven't noticed any difference over the stock plugs or the copper plugs. I am going to wait a few weeks then switch back to copper and see if I notice any difference.

 

OK here's the real deal.

Don't get platinum or irridium if you have a 3" pulley or smaller. They don't last long at all and they do nothing to prevent detonation.
Go with 1 step colder copper plugs. I have had them for at least 6 months with no issues.
Why fix it if it isn't broken? People still want to try irridium and platinum plugs for no reason.
1 step colder copper plugs have been used in high boost applications for years for a reason.

As far as gaps go:

Stock = .45 gap
3" - 2.8" = .40 gap
2.7" - 2.5" = .35 gap

 

Ok, got the NGK7Es gapped at .40 and still getting between 1-5 degrees knock, so I changed to .35 and still the same....I am in cali so the highest octane I use is 91....so should I go down to .30?????

 

I really wish people would quit posting the wrong information, stock gap is .040 not .045

Put a plug in at .045 once and see what happens.

 

The stock gap is .035". I have an 06' and I took the plugs out with low miles and measured them. It is possible for them to open up a little over time with use but the best thing for our cars even stock is to get a set of BKR7E copper plugs and stick them in the way they come gapped from NGK. Don't get caught in the hype - it really is that easy

 

Here is what INTENSE lists as a guide when purchasing spark plugs from them. Personally I'm not a fan of INTENSE, but they have a listing that most people seem to follow, so I guess it can't be too far off.

http://www.intense-racing.com/