Ok, just got back from the track and my car backfires like crazy for some odd reason. I put some hks plugs right before some runs. From 1st to 2nd gear at 8k rpms I hear a loud thud behind me, and same from 2nd to 3rd. Later my friend showed me the video and I seen black smoke and a little spark of fire out of the exhaust. Is this because of the plugs? Never had this problem before.

 

ya man, prolly your plugs, what kind did u take out of ur car in the first place?

 

they were iridium ngk's.. probably tomorow ill switch back but these HKs's make a big difference, and expensive as hell

 

did u have any problems with the iridium ngk's? why'd u switch?

 

switched because one of the cylinders misfired but later found out it was a cracked spark plug. so i put in some old ones in and waited on these to come in

 

i would suggest staying with the NGK's, or get some OEM ones. Idk what type of setup you got but hopefully that cracked plug was just a once time thing. Besides the defect dont replace it if it isn't busted. Some set ups dont require expensive plugs. How did your car run with the expensive plugs in it? jw

 

still ran the same time 14.4 but the engine runs smoother.. but not suggesting for use in around town driving, went 15 miles outside of town and did 6 passes. came there on half tank of gas went home close to empty