should my 97 z28 a4 run a 15.1 with 2.73 gears is there that much differnece between 3.42 and 2.73

 

No, it should run closer to 14.00 with 2.73. Of course that all depends on weather, elevation, shape the car is in, driver skill, etc.

 

My best with 2.73s was a 14.299 with 200 lbs of stereo equipment in the car.

 

could it be my spark plugs it doesnt feel like it is missing but could that be it cuase its got 100,000 miles on it

 

If they are stock, it could be a problem, not necessarily THE problem. Most people don't change spark plugs EVER. But check plugs, wires, opti, O2 sensors, fuel filter, oil filter (ya never know), etc, etc. Basically anything that could go bad. If the owner before didn't take care of it you never know what all could be wrong.

 

where do you live and what is your elevation?
what was the forcast for that day?
how were other cars running that day?

 

With 100k miles on it, it's certainly in need of plugs and could probably use some wires too.

There are TONS of things that could cause slow times.

If your PCM is picking up on knock, then it's pulling timing (sometimes can be HUGE amounts of timing), causing slow times.

Your coil might be getting weak.

The opti might be having problems.

Could be some slippage in the transmission as well.

The best way to go is to put new plugs in it, if that doesn't help, then scan it and see what's going on. Once you've scanned it, then you should be able to make a logical decision on where to go next.

 

well i got the car about a month ago and i ran a 15.1 and 0-60' times were horrible like 2.3's but it will move on the interstate i have replaced oil, oil filter cleaned air filter (k&n) replaced diff fluid trans fluid radiator fluid and i had the cats cut it has helped a little bit but i dont think its runnign 14.00's any sugestions

 

i live in mississippi it was about 70 degrees that night and all my friends were running better than ever one has a 94z28 a4 with cat back cai and was running 13.8's guy witha 2002 gt was running 14.2's and 14.1's all night

 

do a tune up on her. you can see my stock times in the sig. what was your mph? in bad air, the worst time i ran was a 14.79@96mph. i'd say my average time was 14.35@97 and 60's were about 2.20 on average. but whenever i would cut a low 2.1 60' i would run 14.2's or better.
i changed my plugs/wires, filters, fluids, ect. immediately after buying the car so i never got to run it at the track before a tune up.
with 60's like that, i'm willing to bet you've got some sort of an ignition system defect.