Cesarjr23

Hello Every One,

I am just to make my first spark plug replacement and I don't know which Spark Plug choose but better than the stock one. I have read about Iridium Spark Plugs, but which one I choose between NGK, Denso, HKS, or other? Please someone help me to get a better product for the best price on market

Regards,
Cesar

Turboniam

On the DSM 4g63, stock we use NGK BPR 6ES ... however most people go one heat range colder and run BPR 7ES.

They are a $1.50 or so each at Oriellys.

I would "assume" since both the EVO and the DSM have a 4g63, that the same plugs would work well for eachother

Also, platinum and irridium plugs are strongly NOT recomended for turbo cars. None of the DSM guys use them.

CornerHard

Copper NGKs are cheap and all you need .028-.030in spark plug gap on DSMs (though I'm guessing the Evo starts at .028 ). Whatever you do, don't buy those Bosch +4 spark plugs.

EvoDaWayToGo

iTrader: (8)

Try NGKs they are really good and not too pricey

Guack007

What specifically do you "DSM Guys" have against the boshe 4+ platinum and denso iridium plugs. Please dont post "they suck" I'm trying to learn something new here.

jigga

iTrader: (5)

HKS iridium are great, but a little on the pricey side at over 10 bucks a piece. They are able to withstand alot of abuse, very reliable. They come factory pre-gapped so you don't need mess around with gapping.

zookster

and are totally unnnecessary unless you just like to tell people you have cool spark plugs.

the evo wins

iTrader: (3)

exactly

seattle944t

You guys are both wrong. Denso iridium plugs are DYNO proven to improve the ignition system. They require 5,000 less volts to fire and have a .4mm (Thats POINT 4MM) tip that is much easier to fire a spark in high cylinder pressure environments (e.g high compression and forced induction applications). The plug CAN gain horsepower on these type of cars. The reason? Because they will fire a spark in conditions that most plugs wont - so they cure mis-fire problems that are COMMON in high boost applications. This equates to HP. Now if the system is does not have a mis-fire it won't fix anything.

As an example, Import Tuner mag did a test where they only changed the plugs to the Denso's - here are the results on a single page: (yes I know it's an ad, but it's a reprint from the magazine- I have the scans of the article at home)
http://www.autoindustriya.com/ads/denso2.html

As far as which iridium plugs are the best - they are all the same - Manufactured by Denso and re-branded. So which ever ones are cheapest, assuming that they are really iridium plugs.

the evo wins

iTrader: (3)

gary coleman is awesome!

HobieKopek

iTrader: (8)

Jeez, he made a valid point. Just because he said you were wrong doesn't mean that's necessary. Hell, you weren't even completely wrong. Anyway, the pic doesn't work because they don't allow direct image linking.

Generally speaking, what are the advantages of copper plugs over stock (just a lower heat range?) and how does iridium compare to copper given the same heat levels and barring the information already provided?

jigga

iTrader: (5)

std type plugs cannot stand high boost combined with normal driving as well. iridium plugs can,and do. HKS iridium plugs are produced by denso, like seattle944t stated, a by-product of denso.

Evo 7s come with iridium plugs from factory, is mitsu saying something? Why would they spend the extra few dollars per vehicle, which in the production line could costs hundreds of thousands. Could it be that its related to all the complaints they got from evo 5/6 owners who had trouble with their plugs during the colder season? Probably not. I spend 100+ dollars when I change all my fluids, considering the price of fully synthetic gear oil, now why would I replace the plugs with the inexpensive kind considering the fact that plugs don't get replaced that often (every 20k, 25K miles)?

Evos come with NGK plugs, heat range is 7. Highly modified evos usually use a heat range of 8 or 9, but don't expect to run these on an average road car (might get away with an 8). HKS plug grades are codified as follows: a grade 7 is S35, grade 8 (colder plug reccomended for 1.5 bar of boost) is S40 (what I use), and grade 9 (their coldest, used on group a evos) is S45.

S40G (G for evos), which is equivalent to an NGK EVX, is what I use now. The only difference I noticed with both plugs on my evo is that the NGK tends to not like the part throtle daily cruising, its best for hard driving. The S40G works fine, and has satisfied my hungry boost needs. NGK BPR7ES are cheap, heat rated at 7, and works fine on turbo evos (is there another type of evo?). As long as they are properly gapped, you won't experience any misfires at high rpms.

I know that spending double on a simple thing like plugs is really an overkill. But when I see that a lot of my fellow evo owners are all using iridium plugs, even the more experienced guys, then like every car enthusiast I invest on proven experience from others, not hiped advertisement from factory. I've heard tests stating that iridium plug have a better discharge compared to others, but I'm no engineer and cannot confirm that. Well, just my thoughts...

regards, LEE

ShapeGSX

DSMs don't get misfires with NGK copper plugs. Why would an Evo? I've run 26psi with no misfire issues. Stock ignition, too. Mitsubishi makes great ignitions.

Aspen

You can never go wrong with NGK for Japanese cars.

jigga

iTrader: (5)

Well, I guess you guys misunderstood what I said. I never said they were bad. As a matter of fact, I reccomend them over any other plugs out there. I use HKS strictly because of several reccomendations I got from evo owners. Again, I can't compare the two without bringing up manufacturer's claims, yet I feel no difference between the plug I use now (HKS S40G), with the NGK copper. Each to his own. Then again, we all spend money on unecessary things for our cars, don't we?