Well, today I tried the ND Iridium plugs with poor results. I tried them because they worked very well in my blown Mustang. Anyway, my best friend has a Raptor and I used to walk right around him. I changed the plugs and my DS is now BARELY faster. Also, my headpipes are now glowing red. I'm thinking they burn too hot and created a lean condition?

 

maybe try a bigger main jet, or change the clip on the needle.

 

Nobody else has tried these guess? I switched back the regular plugs and am going to try them tonight.

 

If your headers are red, that means your lean, if you jet up, there is the possibility of some extra power when you get the jetting right. Try 1 - 2 sizes bigger, that is all it took on my DS.

 

I run the iridium's in my bike with no problems. What heat range and gap are you running?
Blown Mustang? Details please!



MrHorsepower