Your reaction time was just under half a second, you could shave more off but it doesn't count towards your 1/4 time. What counts more is your 60ft, like whitepearlz said, do you have a copy of your time slip? Let's see it. IIRC, Nissan literature/car and driver etc. says a stock N/A should run about a 15.4 or something like that, so with your mods that's pretty good, and I'm sure you could shave a couple tenths off once you've mastered your launch and shifts.