C-16 spark plug longevity

[squeeze87]

Hi GUys..Last night at the track the car started surging and bucking in 3rd. I'm running straight c-16 and have about 200-250 street and about 10 passes at the track miles on cr42ts plugs. I took them out this morning and they dont APPEAR to be fouled, nice tan color with a little build up on the porcelin. THe coilpack tests good, valve springs are new so thats not it. I guess the real question is does c-16 foul plugs and even though they appear OK they will still misfire under heavy load/boost? and if so how long do they last? I know i can just throw in a set of plugs and see if its fixed, just wanted some input. Car went 11.70's when they were brand new and has gotten progresivly slower every time i have taken it to the track. last nights best was 12.75 @ 93 mph Thanks

oh, EGT are in the 1650 range so its not running lean

 

[Steve Y]

You are making alot of cylinder pressure down low with that cam, and if those plugs are tan you need new ones.....it is easier to fire through the lead deposits to ground than it is to bridge the gap under a lot of compression......Don't forget you are firing through 2 plugs at once.
Tightening the gap a little will delay the misfire for a few more miles.

Steve