I actually have some experience with various forms of racing and I can tell you that 1/2 a second on a 1/4 mile drag strip is actually quite a lot. The same could be said for most road courses. Still all is not lost. As crjackson said NOS is the cheapest and quickest way to gain 100-150 horsepower. He was also correct when he said that things can go seriously wrong when using it. I've seen some rather impressive explosions at the track when things went wrong. So what to do without NOS? I don't really recommend street racing. Besides the obvious risk of an accident especially one involving innocent bystanders the legal costs including loss of your license really dosen't make it worthwhile. Most places have legal drag strips and either a test and tune or grudge night. They may or may not do good track prep on these nights, but it's relatively cheap [ a LOT cheaper than a ticket or any other financial liability you may incur on the street ] and safe. Buy a set of 17x10 wheels and a good set of slicks for a manual or drag radials for an auto and practice a bit before hand. In drag racing your 60 ft. time is critical to getting a good et. Don't worry about trap speed for now, in this case it's ET that matters. Get rid of as much weight before hand as possible. You don't need a full tank of gas to race and gas is around 6 lbs. a gallon. Clean out the trunk and remove the back seat. The seat dosen't weigh much, but removing it and all the junk people generally carry around is easy and FREE. You said you have a '13 so a track key isn't available for your car, but Ford's Pro Cal tune might still be available and while neither of them gives a huge increase in horsepower it should give about a 60 ft. lb. increase in torque at 1,500 rpm which will help with the 60 ft. time so long as you have traction. Driver skill matters in racing especially when using a manual trans
on the drag strip. Practice,practice,Practice.