I think you'll be surprised at what little mods can do. I've only made 3 passes in my car and my best was a 15.3. It doesn't really take much to wake these cars up. Free flowing panel air filter, full exhaust and maybe a tune and you're close to a 15's. Drop some weight and you can be a little quicker. Add good suspension and even better.
Not fast by any means but taking almost a second of the 1/4 time does make the car more fun.