Vax

iTrader: (1)

are they good for nitrous? I know they rule in the forced induction apps, but I plan on going nitrous and this is what im running, should I step it down to a colder plug?

dscott

N20 and iridium plugs are a great combo, and yes, you should knock your plugs down one step colder for anything up to 150 shot. Colder for a bigger shot I think, some of the more knowledgable people should chime in on the heat range.

Airwolf

iTrader: (2)

I run them on a 175 shot. I use the IT20 gapped at .045. My idle is much better using these over the TR6, which are a good plug too. My buddy, 02 Pewter LS1 uses the NGK Iridium and likes them. They are a little cheaper I think.

white2001s10

iTrader: (4)

You might want to contact the plug manufacturer and ask them about the difference in melting point between their irridium tip and the copper they use in their racing plugs. I have a feeling the IR plugs may not be designed for high combustion temp & racing. Hopefully they can tell you the facts.
Personally I am conservative and stick to a racing type of plug like the AR472 from Autolite. Champion makes a good equivalent to this plug as well, but I can't remember the part #.

edit: don't be fooled into thinking that what works great in normal street driving will survive a lot of abuse with nitrous.

XTrooper

I use the NGK TR6IX iridium plugs in my car. Concerning melting points, there's NO comparison in the melting points of iridium vs. copper with iridium being far superior.

Here are the melting points of the two:

Copper = 1981.4 degrees F

Iridium = 4370 degrees F

CAT3

iTrader: (9)

NGK iridiums are about half the cost of the Denso, at least here in Hawaii. I bought, and immediately sold a set of Denso Ir, then bought the NGK Ir and ended having some cash in pocket.

Matt@HSW

iTrader: (14)

I believe that's how they are everywhere. But hold the two side by side and you'll see why the Denso’s are more expensive. With that being said, I use the NGK Iridums most of the time. For some reason the Denso’s are always in our Lightning though...

Matt

Airwolf

iTrader: (2)

I will keep an eye on it. I have only had the IR plugs in since the cam and only 2 dyno runs and a few tuning hits on the juice. No full 1/4 mile runs, yet. Waiting on some cooler weather for good track times.

Vax

iTrader: (1)

I know the denso's rule for FI, ATI recomends them in any of their SC apps.

but if they are that much colder than copper I might keep running them when I go on the DP.

white2001s10

iTrader: (4)

Is that the melting point of pure iridium or the alloy they are putting into their plugs?

XTrooper

Pure iridium, but the iridium alloy used in the tips (for added strength) apparently aren't affected to any great degree as NGK estimates their service life to be 60,000 miles or better in normally-aspirated applications. In any case, the iridium alloy still has a melting point that far exceeds that of both platinum and copper.

Here's some interesting information on iridium spark plugs.

http://www.spark-plugs.co.uk/pages/t...park_plugs.htm

02 Pewter LS1

iTrader: (8)

Dam 175 shot
I run the NGK TR6IX gapped at .040 with my baby 100 shot.
The plugs sell for around $7.00 per plug not a bad price.
I do like the idle with these plugs much better than the TR6 plugs.