What does it take to hit mid 15's quarter mile Options

[94CeliGTguy]

Hey everybody, I have had my 94 celica gt for about a year and have been ok with its acceleration, but I have been researching other cars (and trucks lol) and realizing that it is fairly slow in comparison. I love the way our cars handle and maybe that is all they are good for. I was wondering what it takes for our cars to hit mid 15 runs. I have read all the stickees and have researched 6gc's pretty thoroughly. It seems that stock my Gt should run around a 17 second run, but bolt ons (intake and exhaust) do not greatly reduce perforance in our cars. Without going forced induction or a swap will an intake and exhaust get me in the mid 15 range. Is there anyone on here that consistantly hits these numbers and isn't using forced induction or swapped. I currently just have a intake and am wondering if spending the money on a exhaust is worth it.