http://www.ngk.com/faqmain.asp

Iridium

Iridium is a precious metal that is 6 times harder and 8 times stronger than platinum, it has a 1,200(=F) higher melting point than platinum and conducts electricity better. This makes it possible to create the finest wire center electrode ever. Prior till now, platinum had been favored for long life or performance spark plugs due to its high melting point, also the technology did not exist to machine and bond iridium on a spark plug electrode(at least in a cost effective manner). Iridium industrial spark plugs have been around for years, but still sells for over a hundred dollars per plug. Just now is the technology available to effectively use iridium in a spark plug for automotive applications. The strength, hardness and high melting point of iridium allows NGK to manufacture there iridium ultra-fine wire center electrode to 0.7mm. One of the finest firing points in the industry! (Thus far there has been no problems reported regarding use of iridium plugs with nitrous oxide.)

 

For spray I would rather run with my TR-6 plugs. The problem with platinum plugs and nitrous it that the plugs will glow and cause pre-ignition. If you want to try it, get an AutoTap and watch for knock. I personally wouldn't try it. Stick with what works.

 

he isnt running platnum its iridium(SP?) and its muchh better than platnum.... ive heard good things about it and N20

 

I started a thread about iridiums last year, I ended getting quiet a few pm's from guys that are/were running them, mostly in Vettes. All said they love the plugs, spraya or NA, and non reported any problems. I am personally waiting for the NXL kit to arrive so I can find the appropriate 2step colder NGK Iridium plug and "test" it one a 150DP.

 

I was wondering about the heat ranges. On the above mentioned site I looked up the plugs for my car and it cam out to be a TR55IX so would I just order a TR6IX?

Josh S.

 

Alot of guys are running the iridium plugs in Lightnings and love them with FI. The Iridium plugs are a step or two colder than the stock platinum plugs, I would think the TR55IX's would work fine.