recently i had my plugs changed.the problem is,with my factory plugs i ran a 8.8 at 82.8 mph on a hot day in march and last night after my ngk tr6's were installed i could not do better than a 9.0 at 83.4 at night in about 70 degree weather.the ngk's are they the wrong kinda plug for me? i have a 98 z28 a4 2.73 gears with no major mods.i have a lid,filter,no muffler exhaust.and street tires.please help with any info you may have.also my reaction time last night was a .182 and my 60 ft was 2.161.any comments?thanks also the gap was set at 55

[This message has been edited by tony starr (edited August 10, 2002).]

 

I use TR55's myself, but the TR6's are fine too. Assuming there gap was set properly.

Are you hearing any misfires or ticking sounds (loose plug wire)?

If not, I wouldn't be concerned based on one day at the track. It could have been just a bad day there. The track may not have been prepped as well, more of a head wind, etc... Wait to see a little more.

Matter of act, your trap speed is higher, which is actaully a better sign that your engine is producing good hp.