I need Copper or Irridium plugs that fit the Nortstar , one step colder and having big problem finding. Anybody have any ideas, recommendations. I've ran two bottles of nitrous through engine despite Zex'* advice not to inject with platinum plugs and have third fillup in the trunk cradle and havent used becasue nirtrous destroys platinum plugs fast. ( but the bottle keeps talking to me.....)Please help. I need to lay back awhile any way...At $5 dollars a pound for Nitrous (10 Lb.bottle) and $2.73 a Gallon for premium. The fillups are killin me

Sorry to get off topic but $5.00 lb. for some sauce in ridiculous.

The 4.6 uses the following NGK plugs: Copper TR55, the Platinum is TR55GP, Iridium is TR55IX.

Ya the $5 a Lb is ridiculous but the going rate. And I can (and did again tonite) waste a 10 lb bottle in about 3 hours of "Parkway Fun" , but I have purges that waste alot. But are they ever cool I knew those #'*, ssei1995. My trouble is finding them in at least one range colder. i quess I gotta stop trying to use the computer all the time and call NGK. I was at the lake most of the week and DAM Premium jumped to $3.13 a gallon. Did WE bomb someone else in the middle of the week...... cause that'* ridiculous. Time to leave the Arabs alone and start lynchin Republicans

Three bottles? How big of a shot are you running on that thing?

good god man...you be runnin through the juice...tires gone yet? but uhh yeah, three bottles, on platinum plugs...bad...idea...

I have the 75Hp shot back in till the track here opens, had the 125Hp orifices in last weekend but that was way to much for street use(cant safely hit juice till 2500rpm)
The Tires are fine. Most of my nitrous gets used in bursts from 20-70mph which causes a mild chirp into 3rd gear. I get about 20-25 rolling launchs out of a bottle. Thats about $2 a ride.Zex says expect 8-10 quater miles runs. Getting just under 12MPG after an evening "on the town"

I wish I knew a little more about plugs. Zex has been very helpful but cant tell me what plug....just the kind I need. Something slightly cooler, copper core and electrode, shorter nose if possible. They make a specific nitrous plug with 3 grounds and stubnosed but no listing for the N* And with the plug change a major deal with this motor, I want to get it right the first time.

If you are interested, I got some AC Delco Racing plugs that are colder that will work very well.

Also, you can run the following racing plugs that are colder:

Champion: S57C
Autolite: AR472
NGK: B9EFS

www.sparkplugs.com carries the Champion, Autolite and NGK plugs listed.

ssei1995 are you giving me 3.8L or 4.6L N* plug #'*??? My Bonny has the v8. I would prefer AC Delco Racing plugs

The 4.6 V-8 used in the GXP uses the same plug as the Series 1 Supercharged engine. The part numbers are applicable to both engines.