3gEclipseTurbo

iTrader: (12)

i believe i gapped them to .022. I cant find my gauge. Ill pick one up when i go out later and let you know.

03whitegsr

iTrader: (8)

Actually, it had everything to do with this topic.

His question was "can fouled plugs cause knock?" My point was, yes, it's possible, here are some ways to tell if you are getting real detonation because it's very possible for the plugs to look fouled due to idle conditions yet be perfectly fine and the engine is actually getting true detonation.

03whitegsr

iTrader: (8)

I guess I'm retarded...

What are your reasons for saying they are better, because I've got a bunch why they aren't.

iTune

iTrader: (3)

Here we go again...... Copper plugs will never outperform or outlast a good Iridium plug.....NEVER. I don't care how you spin it. I have done extensive spark plug testing across many different platforms and found this to always hold true in any internal combustion engine. May i remind you i was a dyno tuner and have many years of professional experience tuning just about all high performance platforms on the planet. I worked for some of the top companies in the aftermarket performance sector. So, please understand that i'm not trying to call anybody out here, just want to educate. Nothing more, nothing less. So, please....please don't take offense to this. This is not meant to be derogatory in any way.

Here is why iridium plugs are better than everything else:

1. A spark plug electrode will wear and round. When this happens, it makes it hard for the spark to discharge and jump the gap to the ground strap. The electrode needs to have a sharp edge from which the spark can arc from. If the edges are rounded, the arc is less consistent. This is why i always push the Iridium plugs, because they wear slower and have a very small electrode from which the spark can arc easily, even when slightly worn.

2. As the electrode and ground strap erode, the gap opens up. If you were already very close to running the largest gap you could with your set-up, as these two variables erode, the gap will open and eventually be too big for the spark to jump, under load. Iridium resists this, because it has a very high melting point.

Too sharp a tip will melt the electrode. If the temperature of the tip reaches the melting point of the metal that it's made of - you can kiss it goodbye. Iridium tipped plugs give you the best of both worlds here, because they can have a sharp electrode tip and not melt. Here are the melting points of some commonly used metals (Celsius):

Zinc == 420
Aluminum == 660
Copper == 1083
Steel == 1400-1500
Platinum == 1772
Iridium == 2410

This problem is mainly concerned with the volume of metal at the spark tip - if the temperature even instantaneously reaches the melting point, some of that metal will disappear. You can see that Platinum and Iridium coated plugs can withstand significantly higher temperatures, and thus can have sharper tips than their steel or copper counterparts.

Here are some of the thermal conductivities of some commonly used metals (Watts / centimeter*Kelvin) :

Zinc == 1.16
Aluminum == 2.37
Copper == 4.01
Steel == 0.70 - 0.82
Platinum == 0.716
Iridium == 1.47

You can easily see why Copper is the metal of choice for the core of the spark plug. It's just about the best thermal conductor on earth. But it has a lower melting point, so this does not make it a good metal for the electrode tip but makes a great core, due to it's high conductivity.

So, what we want is the sharpest tip possible such that it does not melt the electrode nor does it stay so hot as to cause pre-ignition and we want it that sharp tip to resist wear, so as to not open up gap...which Iridium does very well.

High boost applications running copper tip plugs will suffer serious plug wear at a very fast rate. Iridium tipped plugs will not.

You will also notice a slight power gain when using a Iridium plug, properly gapped, over it's copper counterpart. This is because the sharp electrode tip is more conducive to spark arc, which allows a larger gap to be run with lower voltage, which exposes more spark to the mixture, thus more power.

iTune

iTrader: (3)

Does it matter that the plugs are fouled or does it matter more, why the plugs are fouled? Super rich conditions can cause knock(pre-ignition) and foul plugs....so we're past this now. The why is what we're after, because this is what can be causing the knock, not the fouled plugs alone. Fouled plugs are just a sign of the why.

By coming in here and stating the obvious, you're confusing the people that don't understand any of this. I'm trying to keep this discussion on track.....the more we toil over semantics and the obvious, the more people get lost.

03whitegsr

iTrader: (8)

You aren't the first expert to come on here proclaiming their extensive back ground. I don't care.

I will continue to disagree with iridumims being better simply because of the small tip means a high tip temeprature which will lead to pre-igintion. The low electrical conductivity will increase that issue. I will continue to prefer copper plugs changed at every oil change.

The rest of the question made no sense to me. If the plug isn't fouled under heavy load but only at low engine speed, then I would say "yes, it matters that the plug is not fouled while the ECU is sensing detonation and you may actually be getting knock."

iTune

iTrader: (3)

Lol...you obviously don't get it....and that's fine. I'm cool with where i sit in the scheme of things buddy. In the end, it's your car....do what ever you wish. If you're getting pre-ignition from your Iridium tipped spark plug, you aren't doing something correct(i.e. improper heat range, insufficient gap)....that's your fault, not the plugs.

03whitegsr

iTrader: (8)

Nope, I'm cheap and that's why I don't run iridium. But I don't mind changing plugs every 3k, I actually prefer it as I prefer to regularly monitor combustion characteristics of my motor.

But that's separate from my other reasons of not running them.

If you just want to toss a plug in and forget about them, yeah, Iridium plugs are better.

Ted B

iTrader: (6)

It's interesting how I've always seen everyone refer to the conventional NGK plugs as 'copper'. In fact, the conventional electrodes are a nickel alloy, not copper. FWIW, pure nickel has a melting point of 1453C and a thermal conductivity of 0.907 W/cmK.

The conventional plugs are obviously cheaper, and don't last as long due to the erosion of the electrodes. The smaller iridium center electrode tips require less voltage to fire than the conventional (nickel) plugs, and obviously are more durable.

Also, there are two different types of NGK iridiums that are relevant to our application. One is the very expensive OE Laser Iridium, which features the iridium center tip, plus a small chip of iridium welded to the ground electrode. I've been advised to avoid this plug for extreme duty, but it seems that everyone who uses iridium here foregoes that option anyway for the less pricey, single iridium plug (e.g. BPR8EIX). I've wondered if this plug actually lasts much longer than the conventional nickel plug, given it's nickel ground electrode.

Anyway, some notable shops here (e.g. English Racing) use only iridium plugs, while others stay with the cheaper conventional types. Iridium plugs apparently don't present the same sort of ills that gave platinum a bad rep with FI apps, so take it all FWIW.

iTune

iTrader: (3)

I think you see the conventional NGK plugs refered to as copper, because the electrodes are copper and then plated with the nickel alloy. The Iridium plugs are copper cored with the fine iridium tip welded to the electrode. Calling them copper is kind of a misnomer, but people do it, myself included.

The ground strap of the NGK Iridium IX plugs do wear, but because there is so much material, they wear slowly. Most of your wear will come from the electrode, not the ground strap, regardless of plug type. Iridium tipped plugs will resist this wear much greater than the copper/nickel allow plugs.

English Racing recommends the Iridium plugs for a reason. They out perform and out last. Ultimately, you guys can run whatever you'd like.

Also, you guys should know, that the NGK Iridium IX plugs have a 2 year replacement warranty on them, direct from NGK. NGK will replace them if their under 2 years old and wore out. I personally have not bought a set of plugs in 5 years. I get mine replaced every few months, no questions asked. I have three sets i run in rotation.

If that's not enough proof to warrant the use of Iridium, i don't know what is. But again, you do what you want.

03whitegsr, what power levels are you running? What heat range plug? What gap? stock ignition or aftermarket?

nightwalker

I use to believe the "copper plugs" are better banter, but after a crap load of copper plugs wearing out on me, I changed back to iridium (Using Denso IW24's) and have not had any fouling for the last 6 months.

I did notice that the Iridiums didn't get the spark blow out at 25psi (pump gas) that I was getting with the coppers.

People can believe whatever they want, all my datalogs, and experience tells me that Iridium is better.

colocho19

Are all the spark plugs black???

3gEclipseTurbo

iTrader: (12)

Ok well i cleaned the plugs, got them a medium gray color and put them back in drove the car around the block and there black again. The afr where alot richer than they were before, was 12's when on the throttle. Why would my afr be richer after i cleaned the plugs? And there black again.

dastallion951

well to add my 0.02 since u running rich becuz ur plugs are gettin black on u repeatedly...whats ur stft and ltft trims running at??? if there off then ur tunes gonna be off???

iTune

iTrader: (3)

You're running so rich, that it's causing mis-fires, which will read lean AFRs. Once the plug mis-fires enough times, it will foul completely. Running this rich will also cause knock all on it's own. I suspected this, which is what i was trying to explain to 03whitegsr. It's the why i was referring to.

Clean the plugs again, lean out the fuel 5% before you crank the engine, then start re-tuning AFR. What are you gapping the plugs to? I suggest .025 to start off, to ensure a medium gap. Then, once you have AFRs good, gap up to .028 and work your way down until you have no misfires. This will ensure you have the proper gap dialed in. Tune AFRs for 14.7:1 at idle(no leaner than 15.6:1), and part throttle(up to 0psi, 13.5 psi up to 5psi, . 12.5:1 during spool up tapering to 11.5:1 at peak VE, tapering to 11.1:1 after 6000rpm. This will get you in the safe zone, while you sort everything out.

If you have any further questions, let me know.