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Here Alot
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Discussion Starter #1
Now, can anyone tell me why NGK homepage didn't have Iridium plugs listed for our cars? What is the part No. for it? Also, I am going to install boost control. Is that better than Platinum? What is the difference between Platinum and Iridium? Which is better?

Thanks
94 VR4
 

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platinum is a mineral, Iridium sounds radioactive. Could be something found only in comets & asteroids
 

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Platinum is an <B>element</B> :) as is Iridium. Pt is 78 in the Periodic Table and Ir is 77. That means they are very similar property wise.

Get copper plugs. They work just as well performance-wise and only cost $1.60 each.
 

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Here Alot
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Discussion Starter #4
Periodic Table ??? lol.. come on guys. If you have one choice to pick either Plat. or Iridium? Which one would you pick? Plat. $9.99 each, Iridium $6.99 each.

Thanks :)
 

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NGK has Iridium plugs (Iriduim IX) that will work with our cars but they are gapped at .044 and they don't recommend changing the gap. The .044 is the factory gap and will work fine on an unmodified car. If you crank up the boost (even to to say 14 psi) you will probably see spark blow out problems that require dropping the gap to the .032 to .036 range. I discussed this with NGK last week. Their recommendation- stay with the Laser Platinum Plug (factory spec plug) and drop the gap.

Then I talked to Denso who also makes a factory spec Platinum plug for the 3s cars (the other listed plug in your owners manual).

They recommended their Iridium plug but one heat range colder and with a reduced gap for a modified engine. So instead of their IK20 (.044 gap and the recommended plug for our car stock) they said go with the IK22 (one heat range colder and set to a .032 gap). They told me that it is not recommended to use the IK20 and re-gap it in a car that is modified to for another 40 or more horsepower using higher boost pressure o get the HP. Doing so will cause the plug to run hot and the gap will open, in some cases the plug ceramic can crack.

I've decided to go with the Denso Iriduim's and give it a shot. Price from Monarch (SparkPlugs.com) is virtually identical for the NGK Platinum's and the Denso Iriduim's. If cost was the driver I could get the Denso Platinum's for half that. As Jeff points out the Copper's are still cheaper although the life will be much shorter between plug changes. Bear in mind I'm taking some risk buying the Iridium's. The NGK Platinum's have worked well for me but now I must re-gap for the higher boost so I'm in the mood to play around.

Chris
1994 VR4
 

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blingalicous
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...

i read on the supra forums that keith ta's supra(made 766 hp on 18 psi) made 30 horsepower just by going to iridium plugs:confused: :confused: :confused:
 

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IDIC
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i read on the supra forums that keith ta's supra(made 766 hp on 18 psi) made 30 horsepower just by going to iridium plugs
Mabey because they run colder, he could turn the boost up a little? Or perhaps he just gapped them down and turned up the boost..I'm very skeptical that <$60 in spark plugs could produce that much horsepower...but hey, if it works, that's great :) I've got a set of Denso Iridium's sitting in my closet I need to install =)

-Aaron
'94 R/T TT
'95 VR-4 Spyder
'95 Pearl Yellow R/T (belongs to Mom)
 

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Why does everyone argue?
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MATTRED3000GT- Platinum plugs are generally cheaper then Iridiums just so you know, the only reason we are getting them for 6.99 is because of the group buy. Most places charge 15-18 a plug for iridiums. Iridium is the better was to go. smaller tips, higher melting point, better conductivity, etc...
 

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Here Alot
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Discussion Starter #9
So we can't regap the Iridium right? How much will it hold from the boost control? 14psi? Thanks
 

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According to NGK they do not recommend re-gapping the Iridium IX plugs.

Denso says it is okay to do so, however they want you to be sure that you select the correct heat range.

Chris
1994 VR4
 

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blingalicous
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shouldnt be too much longer....the valves, block, and heads are already at gtpro, so the only thing left is the headers for the 399's.....:)
 

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Zentelis said:


Mabey because they run colder, he could turn the boost up a little? Or perhaps he just gapped them down and turned up the boost..I'm very skeptical that <$60 in spark plugs could produce that much horsepower...but hey, if it works, that's great :) I've got a set of Denso Iridium's sitting in my closet I need to install =)

-Aaron
'94 R/T TT
'95 VR-4 Spyder
'95 Pearl Yellow R/T (belongs to Mom)
Simple - his other plugs were worn out. He could have probably put in $.050 plugs and gotten the same gain. Thats probably why they are replaced. I put my iridium's in a couple weeks ago, and I'm really unimpressed. My nitrous is on the way, and I think i'm gonna go w/ copper.

.jon
 
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