Well you got an intake, your next step should be to modify your exhaust system. Start out by getting a cat-back. Since your going N/A, your should look into a 2.5 inch. These 2 companies offer good ones. Borla and MBRP. The Borla gained 4whp and 3lb/ft of torque. Well the MBRP gives you 3whp and 2lb/ft of torque. Both are stainless steel too.
After that, you should decide wether or not you want a shorty header or race header.
EDIT> This is what you'll want to do. Finish off your exhaust. Decide wether or not you wanna ditch your catalytic converter and go with a race header (illegal) or if you wanna go with a shorty header and install a high flow cat on it. You could also get a flex pipe if you wanted to. After you have that finished up with, you might want to look into a ported and polished head, the Ford Racing one is a good choice to go for. You'll also want to get new camshafts, stage 2 would be a good choice if you don't want it to be too aggressive, or if you don't mind having an aggressive car, then go with stage 3. Be careful though because most stage 3 camshafts require a compression ratio of 10.5:1 or higher. If you do decide that you want more compression ratio, get it by milling the cylinder head to get a 10.5:1 or 10.7:1, it will require the use of higher octane gas though. Another thing you'll want later are adjustable cam gears since the stock cam gears are not adjustable, even adding cam gears now can show an increase of power, even without a exhaust setup. You might also want to look into an aftermarket intake manifold, the one you should go for is the Ford Racing one. It requires some machining to get on but would be nice. A 65mm throttle body would be a good thing to get too. Don't forget to upgrade your fuel injectors, 30lbs would be good because the stock 19's won't work well (more HP means getting more airflow and fuel flow, you can't have alot of HP and be runnin on stock 19's because the engine won't be getting as much fuel as it needs) . Well that's about all the engine mods, your next step would be to modify the drivetrain. Get a Torsen or Quaife differential, 4.06 gears, clutch and flywheel. Well you can't forget brakes, you will need to uprgrade your brakes. Get new rotors and pads. I'd suggest going with slotted rotors since some drilled rotors can wrap. Hmmm well that's about it for Engine, Transmission, and Brake mods. Get yourself a nice suspension kit and rims and you'd be all set.
Also, since your driving an automatic, you will benefit from a upgraded chip, they'll raise the speed limiter and rev limiter. Will also improve the shifting, this is why an automatic benefits so much from a upgraded chip. But finish your exhaust system first. That way you'll have a killer sound and more power.
Well it depends on what mods you get, what stage cams you get. Focus Central built a NA focus that runs in the 12's but it is for racing only. You could prolly get in the mid-high 13's or low 14's. If you don't mind not being able to take your friends around, then ditch the back seat, front passenger seat, the spare and jack. Weight reduction helps alot. What is this car gonna be used for?
OK lol, well that was just an idea. So you want a daily driver N/A car. Aight, well go with stage 2 cams, since they aren't so agressive. Just remember if you have a N/A motor, you will have to be revving the shyt outta it!! Do you think your gonna raise the compression ratio in it? Once you get your cam shafts and cam gears, go to a dyno and tune shop. Get your car dynoed and your cam gears adjusted. But when you get your camshafts, line them up to TDC. I'm just curious, is this gonna be like a project. Where you save up money n then get parts and there is no time limit? like are you on a tight budget?
Well the original compression ratio is 9.6:1. That's not a bad ratio to go up to, tho you could go up to 10.7:1 and still be safe. That's the problem with milling the cylinder head, is you have to be careful of cylinder volume, and leakage.( i think that's what it was)
Well unfortantly the automatics don't take it too well with nitrous, yes you can run nitrous but with an automatic you MUST be careful because the transmission can't take it too well. I think a 50 shot would be good, and if your planning to go with nitrous then stay with your compression ratio.
Well PROJECT ALL MOTOR is a car project I'm doing. I was gonna go forced induction by getting the Jackson Racing supercharger but later decided I didn't want to. I decided I didn't wanna use force to power my car, so I decided to do it all motor. I'm actually almost done with engine mods. Gotta get a ported and polished head, get it milled to raise the compression ratio, get camshafts, cam gears, intake manifold, 65mm or 70mm throttle body, 30lb injectors, MAF, chip, and ditching my MAC intake for a volant one. Hmmm I really don't know how fast I'm planning to go, I'm just gonna build it up till I'm done. I'm not to concerned with hp, I'm more concerned about torque, I want to have more torque then hp.