i think I wanna try the iridiums, I think I'll have to change the coppers too much...

ADAM, please let me know which Denso I can use in the EVO that will run coller than stock for higher boost levels...THANKS

-Shahul

 

I run my copper plugs for 6 to 9 months before I replace them. And even when I do replace them, they still have life.

I run 16 to 19psi of boost daily (depending on my mood), and 24 psi at the track.

You won't have to change them that often.

Oh, and I run the stock heat range, which is BPR6ES. I've never held much stock in the whole colder heat range thing. I have run BPR7ES, as well, which is a colder heat range, but I saw no difference in the car (no knock, no fouling).

 

the cooler spark is a "preventetive maintenace" thing I thought.... but thats only if your doing 20+ daily which I am doing about 20.5

How often are th stock plugs supposed to be changed(lazy to read manual).... and arent they already Iridium?

-Shahul

 

HOLY F*CK
The Stealership wants $30 PER PLUG!!!!!!!!!!!!!!!

*** Raping anyone???

 

$120 for Iridium plugs? Or $10 for coppers?

And yes, the stock Evo plugs are Iridium.

 

Yea no ****, $120 for Iridium~!~!~!~!~!~!~!~

Im either getting a bad misfire in 4th, or im hitting fuel cut. Fuel cut is more of a you-hitting-brick-wall-then-again and the misfire is just like a one-time-you-hitting-brick-wall.

My guess is misfire, thats why I want to change plugs.

 

A misfire doesn't feel like hitting a brick wall. More like a brief stutter.

 

I PMed you Shape. If it was a misfire, I should be getting it in every gear. I'm only getting it in fourth... around 4000rpm, but after that everything is kewl...

 

thats the dealership, you can get them so much cheaper

-Shahul

 

naaa its not missing. I was boosting too much. Back down to stock boost and no more hitting the brick wall.

Sucks I cant run 1.5bar... car feels slow at stock boost now! I have seen the light and I cant go back!!!!!!!!

 

The spark that jumps the gap of a spark plug is determined by the pressure and fuel condition in the cylinder and the resistance of the plug, wire (if present) and coil. For example it takes say 20,000 volts to fire a plug in a rich cylinder and 40,000 to fire in a lean cylinder. Plugs do not determine the strenghth of the spark. The resistance of the plug should match that of the original plug that the iginiton system was designed to use.

Most direct ignition systems are capable of 80,000 volts. The "waste" spark has no bearing on the original spark because that cylinder is always on it's exhaust stroke and offers little resistance to the spark jumping the gap. A DIS system is often better because it is capable of generation more amps than normal ignition systems. There for the spark is hotter. Amps are the real potentcy of electricity. .1 of an amp will kill you. 100,000 volts at say .01 of an amp is relatively harmless. You'll feel it but it won't hur t you.

Spark plugs actually fire from the ground electrode to the center electrode. That is why a worn plug has a rounded center elctrode. It is from the spark "burning" the edge off. Spark likes to jump from a rounded surface to a sharp edge. Hence the ground electrode is design as it is and the center electrode has nice sharp edges. It's kind of like lightning. It doesn't actually strike the ground but the negative electrons travel up to the sky. The light you see is the after effect. All electricity actually flows from negative to positivve, it is the flow of the neg. electron that makes electricity.

The small center electrode plugs suck because the surface area for the spark to jump to is small. It may require less energy but you will get a larger spark on a normal electrode. Look at a spark plug when it fires. It is not 1 simple spark but more of a broad spark. On a small center electrode there is less surface area. Especially in the case of a boosted car because the cylinder conditions are more demanding then an N/A car. This is why they are generally not recommended. Normal plugs or the larger center electrode are clearly better. Plugs like Iridium are harder surfaced for wear resistance. The monir amount of electrical resistance they offer is minimal and they last longer.

Edit: The spark plug heat range is a measure of the plugs ability to remove heat from the combustion chamber and transfer it to the cylinder head (cooling system). The colder plug is generally shorter and has a faster heat path, there for it keeps the cylinder cooler. The olny issue is, the plug must stay hot enough to prevent fouling. The tip temperature needs to run between 500C-850C to avoid cabon deposits on the electrode. So a 7 is better provided that the tip temperature can run in that range. Because it is more recessed from the cylinder it is more difficult to keep it's temperature up. This is why you see cold plugs in high HP engines, more combustion energy in general. If you run your car hard or do a lot of highway driving, you can get away with a colder plug but if you do a lot of slow stop and go then the 6 would be better.

 

ShapeGSX,
I am suprised you don't seen any benefit from a colder plug like the 7. You are certainly running the boost (especially at the track) to benefit from extracting more heat from the cylinder and reducing the chances of preignition. Then again 1 heat range change is not a huge leap, comparatively. It would be interestingto take a car that pre-ignites and test the different ranges to see the effects.

 

Don't need to specify whether who's wrong or right .. the engines are TOTALLY different .. but don't take my word for it.. if you get the chance.. compare the 2 side by side ..

FYI even a EVO IV engine is different from the VII .. and this engine share an even more common background than the eclipse 4g63 which share a common ancestry with the evo I to III and the older galant VR4 ..

The evos have their ups and downs good and bad .. they are not as hyped up as the USDM buyers make them to be.. same to the Skylines .. the myths and the invulnerability that is generated by the domestic market because of unavailability of these 'racecars' will be gone as Evos become another common car like the Rex ..

Good luck !!

 

I have compared the 2 side by side. They have a lot in common.

Differences:
The Evo's block is rotated 180 degrees in the engine bay. In other words, really no casting difference. They just put the engine on the other side of the engine bay.
The Evo's head is mirrored left to right in the engine bay. Definite casting difference here.
The Evo's intake manifold is lower and has shorter runners.
The Evo has a serpentine belt instead of the 3 belts my car has.
The Evo has a coil on plug wasted spark ignition as opposed to the remote coil wasted spark ignition on my car.

The initial thought may be that there is nothing in common by looking at them. But there isn't anything that really makes them operate differently. And operation is the important thing.

On top of this, the engine computers in the 2G Eclipse and the Evo appear to have most of their major functions in common (as is stated in the Evo's Technical Reference Manual).

Frankly, all the stuff that makes any difference when it comes to getting a spark to fire in the combustion chamber is the same or better with the Evo. Copper plugs will work fine.

I'm telling you why they will work fine.

Why don't you tell me why they won't instead of just trying to tell me that they won't?

 

Go ahead and plug an eclispe computer into the evo and see if it runs ..

Try bolting the head and manifold from the III (eclipse engine) to the VII .. they don't bolt up ..

The cams don't work since you agreed the engine is rotated.

The crank don't work since they are rotated ..

you probably can use a VII piston and maybe the conrods .. even the valve and springs .. maybe .. but other than that .. that's about it ..

Actually.. you didn't tell me why they work .. since you didn't try bolting them on .. just that they appear to be workable..
I don't have to tell you what else and why .. you're smart enough to figure that out instead of insisting they are .. since you have the 2 engines in pieces side by side .. put them together and then tell me what work and what doesn't because I don't know what else

As for the ignition coils .. they have the SAME part number as a MIVEC engine (a model that's not available in US) .. a 1.6 NA engine .. again .. if they are as powerful as you mentioned .. then a gap difference of say 0.1mm will not hurt anything .. and that's what happened .. mine was gapped 0.9mm 0.1mm wider than normal .. on HKS iridiums .. they misfired at 1.35bar passing 4000rpms .. just check around .. ask any evo owner to check the gaps and regap them just 0.1mm wider ..

The way you put it .. all engine work the same way as the 4g63 since all of them operate the same way ..

Don't think we have to continue on with this .. the original post was asking what plugs help ..