Contour Enthusiasts Group Archives Forums Modifications Duratec Performance spark plugs

TR55IX is the cross matched plug to the AWSF22FS Motorcraft Plug. AWSF32P is 1 step hotter and apparently was used on all models 99 and back. If you have noticed any problems with pinging or hesitation, you may want to consider going to a colder step plug. The only problem is NGK doesn't make one colder, Denso does though, if you're interested just send me an email, it's in my sig....Aloha, Micah

PS- Unfortunately I don't have an answer on the Autolite Plugs at this time...

what would be the best plug to use in my 98 svt countour with nitrous ?

I thought Iridium was used to frost lightbulbs and make the tips for ball point pens?

At least that's what I learned in grade school Chemistry...

What properties does Iridium have that makes it a good material for spark plugs?

This is interesting...

i have some ngk iridium ix for sale if interested? they are really good plugs good if u wanna drop nos too

i have some ngk iridium ix for sale if interested? they are really good plugs good if u wanna drop nos too email me if u want them nossvtcontour@aol.com

As far as Iridium, we need to just wait and see how they go on my car!! The NGK or Autolite Platinums are great plugs and support what there designed for.

I have no clue to your comment, never learned that one in Grade School!!

Here's a bit of a description to why there so good! Iridium has a Melting Point 700deg.C above platinum and is the main reason why in order to weld the Iridium Electrode onto the Plug, Denso needed to use a 360deg. Laser Process as the normal welding process used on copper and Platinum Electrodes couldn't melt the Iridium. In order to avoid oxidation over 900degC a bit of Rhodium is added to the Iridium. Especially Unique and currently incapable by any other Manufacter is Denso's Ultrafine .4mm Electrode (NGK also knows the benefits of a smaller electrode and has there Iridium plugs at .7mm, although there Technology doesn't allow them to go any smaller at the moment).
This increases firing performance by decreasing firing voltage, on average 5000 less volts are needed compared to a conventional plug. This as well as Denso's patented U-Groove results in less Flame dissapation making the spread of the flame nucleus easier and therefor yielding greater firing energy. the Groove allows the flame to grow in, thereby creating a larger flame front for commplete combustion. On a conventional plug the flat electrode design crushes the spark and the overall volume of the flash front is smaller.

Aloha, Micah

I think the only issue, like Hightower mentioned, is longevity. Because Ford apparently uses a EDS ignition system the spark goes through the core and the ground for optimum spark flame front. We won't definately know how long these Iridium plugs will last unless we try them, so my purpose in doing so. I guess I'll cross my fingers and hope the nickel Ground Electrode will hold up, I know the Iridium side of the electrode will. The plugs go in today!!!

I used to work @ Pep Boys, and one day we had this guy come in very upset. I guess he put the Bosch +4s in his Dodge truck and one of the electrodes fell out of the plug ! He had the plug with him, along with a mechanic's bill for cylinder damage. I have never heard of this happening to anyone else, but it sure scared me!

OK 'aftermarket engineers' define why you need to change the heat range and 'hardness' of a spark plug.......I'm gonna love this....