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Discussion Starter · #1 ·
Just got a call from the SVT tech who's performing my head swap (Tick TSB). He asked about my NGK TR-6 plugs I have installed and wondered how long they had been in the motor. My car had about 3K miles on it when I installed them and it has 7500 now so they've been in for 4K miles. The tech said they were completely shot! He noted they were very burnt and appeared to be damaged due to excessive heat. He even said one of them appeared to have no gap left at all!? I gapped them at 0.040" initially and was very careful during installation so unless the piston came up and kissed it I don't know how that would have happened. He told me that the NGK's are not designed to handle the high heat generated by the Cobra's supercharged motor. I told him to go ahead and replace them with a set of stockers.
Just thought I'd give all the TR-6 users a heads up to pull a plug or two and check them out...

U.M.

BTW - My motor is still running the stock pulley and no chip. Just the mods listed in my sig. I will admit thought that my A/F ratio is a little lean on the bottom end and I'm thinking this may have contributed to my plugs early demise...
 

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Night Trains Daddy
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I'll be sure to check mine soon...I've had 6000 worry free miles with them...and the car is running real good...hmmmmm
 

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Discussion Starter · #3 ·
stlblack03 said:
I'll be sure to check mine soon...I've had 6000 worry free miles with them...and the car is running real good...hmmmmm
My car seemed to be running good too! Right up until I was scheduled to drop it off for the head replacement, then I suddenly had problems with engine surge under boost! Don't know if it is the plugs or the FRP sensor. The tech saved the plugs for me and I'll report back once I get my hands on them.

U.M.
 

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I've got 3,000 miles on mine, runs fine. I have used them in my Lightning for about the last 18,000 miles. Lightning guys have been using them for years. A lot of the really fast trucks too. If you have burnt plugs then that is a tuning issue most likely. -Mat-
 

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The 03 Cobra came with three heat ranges of plugs; AGFS-32/22/12. Mine came with AGFS-12. they are two heat ranges colder than the TR-6s. You should use the AGFS-12s or equal plugs, TR-4s or IT-22s. I run IT-24s with on problems.

AMB
 
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