Next time at the track I`m going to kill the engine as I go thru the traps (and at different RPMs) in order to read my plugs. What exactly do I look for? I`ll have one of those lit/magnifying tools to check them so please be as specific as you can. The plugs are NGK R5671A-9 as recommended by John Phillips from NX.
Thanks,
Glen

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91 Z28 406
11.34 118 N/A
10.36 130 N2O

 

You want to look at the porcelain at the base where it touches the plug edge. This are should be lightly tanned. The top of the porcelain should look like its brand new. Look for "pepper" specles on the porcelain as well. This is sign of detonation. There is alot more to it then this, but thats the basics.

 

To check for the pebbles (detonation), you don't need to do it immediately. They stay on the procelain til the next time you go WOT.

That's really the important thing to watch for. I've taken my plugs out much later and can still read them.

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SSMOKEM

1995 Impala SS "Cherry Bomb"
Best ETs: faster than my '65 pickup
Mods: 93% stock

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