I will echo most of the comments here. Achieving the "magazine" published quarter miles are typical your best case scenario bearing in mind some are theoretical numbers based on track conditions and weather.
Track prep and weather variables will play a major role in what you can run take into account humidity, temperature, headwind, etc also pay close attention to track preparation.

A couple of pointers regarding improving your "stock" numbers are:
1. Reset your throttle
2. Don't race a full tank
3. Pay close attention to engine temps (dont drive 80mph to the track for 3 hrs and expect to immediately make a decent pass)
4. Check tire pressure, lower pressure in the rear can improve traction (not likely an issue on bases and limited unless poor track prep) slightly higher pressure in the front can reduce friction.

As for more power (as much as I hate the response) an srt is a better value than modding if you are looking for high hp/or competitive track times. Otherwise look into the vendors mentioned for CAI, injectors, tune etc.

I'm no expert and have only tracked my car a few times and my base model (6sp) consistently ran 15.130-15.177 (always at 93mph) with good track prep and 3/4's full of fuel. Unfortunately this is also after about a 2hr drive to the track and only about a 5 min cooldown. Based on my lack of experience with drag racing (only my second time) I think a good driver could get a base into the high 14's but dropping a second off that is going to get expensive.

For those who can make sense of the numbers below is a slip from my first pass.
Perhaps someone can indicate the weak points of these cars in stock form.
I was likely a bit conservative with throttle off the line as it tended to bog a bit at launch.
My best time was a 15.130 with a r/t of .065

Slip03.jpg?t=1269916230