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My 120k service is coming up soon, and I was considering using the Denso Iridium plugs. Does anyone have any experience with these plugs in a base for daily driving?
 

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High Boozemaster
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ha ha ha, i saw those on ebay, the guy wanted $75 for 6, and he said they were dyno tested on a 1.8L civic, and it gained 60HP!!! then he said they would add 21HP on a 3000GT!!

first of all, how would spark plugs add 60HP on any car? and second, how would they add more power on a civic over a 3000GT?

i just thought that was funny, but yeah i hear the denso plugs are good & so are the NGKs...
 

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Detroit RiceCop
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Dude, of course it adds 60HP on a Civic. Every ricer knows this man. If you take a red marker pen and put an "R" on each plug, you'll get an extra 5HP per plug too.
 

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I read an article in a magazine a few months back where they swapped plugs in a car and dyno tested it the car was civic or something and they did get a significant hp rise {9-12hp} but the plugs in the car to start with where copper and had been in the car for awhile so this could have been part of the increase in hp.None the less the magazine said it would have been even more of a benefit if the car had a coil pack{distributerless} ignition like our cars . I dont think there is much of an advantage over the laser platinum plugs our car comes with standerd.
 
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I have heard BAD things about the Iridium plugs. Do a search, there are threads on this!!
 

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I was thinking about getting some Iridum plugs myself but save us the trouble of searching & just tell us what you heard. That way, we can draw a conclusion:D. Yeah I know, I'm just a lazy bastard huh:D?
 

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perpetual college student
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I think the consensus is pretty much to make sure you go at least one heat range colder than stock if you are planning on running any increased boost (for iridiums, but applies to others as well). People were not having success with iridium plugs that were at the same heat range as stock, when they were running increased boost (even if just the standard 15psi on 9b's).

There were some other problems though, such as on XWING's car which I think ate some iridium plugs. I am not sure of the heat range he was using though.
 

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Premium Member
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$75 for 6 Denso Iridium plugs isn't a bad price.. I've seen them sold for $15 a piece:eek: I bought some because I wanted to go with something other than NGK and will be installing them on my car in a couple of days.
 

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So basicaly, if you want to raise the boost levels to 18-20psi providing you have the adequet fuel system set up & want to use Iridiums plugs; you'd want to get one heat range colder than stock, right?
 

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What about the NGK-R plugs? Are those sufficient to Iridiums? What's the heat range on those?
 

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I have Denso's on my car and they work fine. The car runs a lot smoother, and more responsive. I also have a non-turbo so I don't know how they are with the turbos. The NGK-R are awesome, I'm going to get a set here in a little bit. Also I got my Denso Iridiums for $58 bucks for all 6 with shipping. 75 is too much, shop around.
 

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perpetual college student
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the general rule is one heat range colder for each 100 hp over stock, so if you have upgraded turbos running 18 psi, I'd say 2 heat ranges colder. If you are running stock turbos, 1 heat range colder should be fine.

Where'd you get yours at kdog? Don't be mysterious :p
 

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What's the heat range on the stock NGK plugs? What's the range on the NGK-R plugs & are they just as good as the Iridum plugs?
 

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NGK Product Lineup

Doesn't NGK make Iridium plugs too? Has anyone bought them & how do they compare to Densos price & performance wise?
 

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i'm getting denso plats in a couple of days from discount auto for $6 a piece here in florida.
 

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Vr-4 Evr
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i've read an article before where they DID get a 60HP increase on just changing the spark plugs alone. Of course it depends on your setup on a stock car it wont make that much difference but if your is seriously modded it will make a difference.
 

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VA Turbo
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I have Denso iridium plugs and I am having my motor rebuilt with upgraded turbos and fuel system, what heat range should I be using?
 

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Wizard of NOS
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mitsu3kgt311 said:
ha ha ha, i saw those on ebay, the guy wanted $75 for 6, and he said they were dyno tested on a 1.8L civic, and it gained 60HP!!! then he said they would add 21HP on a 3000GT!!

first of all, how would spark plugs add 60HP on any car? and second, how would they add more power on a civic over a 3000GT?

i just thought that was funny, but yeah i hear the denso plugs are good & so are the NGKs...
I saw those on Ebay they werent NGK or Denso, they were a knock off called IX's or something like that.

Iridium plugs are suposed to be really god for cars running Nitrous, there even suposed to be better then copper.
 

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perpetual college student
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DrewVR4 said:
I have Denso iridium plugs and I am having my motor rebuilt with upgraded turbos and fuel system, what heat range should I be using?
1 range colder than stock, unless you are planning on running 20+ psi, in which case 2 ranges colder
 

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VA Turbo
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Thanks billvp, I will follow the recommendation.
 
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