Originally posted by DessViperV-10
well,you can but many things,flowmaster exhaust,aluminum heads,k&n air-filter,new spark plugs,intake,and well you can get a eldbrock carberator for 200 USD
Um... don't listen to the above at all....
Ok, to make 250odd HP with a stock motor, you are going to need to do some things.
1st, reduce your rotating mass of the engine. so, in other words, forged alluminium rods, pistons ect. Pistons that are possibly
around 11:1-12:1.
You will need the stock Alluminium head to be ported and polished at least, possibly put on a flow bench to achieve a better flow characteristics. You will need an upgraded set of cams, possibly with more lift and duration, again, depending on budget, larger valves.
Again, as with the turbo, you will need upgraded injectors, and possibly a chip UPGRADE (not reprogram)
And air filter will possibly help, but if you want to acctually improve preformance, a relocation of the airbox/intake will be nessesary. There are many kits that will help this.
Actually, contrary to popular opinions, spark plugs do NOT need to be changed over. Most import's use NKG plugs, which according to lots of friends with cars that have experimented, are just as good as the GOLD serise, which I seem to recall running around 10 a plug.
Ignition systems can be upgraded, and will probably will need to be to make this kind of power.
Another consideration is bore & stroking your motor to allow for a larger displacement. This is really a idiotic thing to do unless you are at the top displacement honda offers. So if you go this route, look into swapping a b18, or a b20/b18head combo in, it will save you headaches, and give you another camshaft.
Also depending, you can increase the quality of lifters and rockerarms to allow for less resistance, meaning more horsepower. Changes to the valve springs can be made to allow for more revs, which in turn with more mods, will allow more horsepower.
Unfortunately, unlike american motors (read: cam in block v8's) there are no kits with a specific output that is advertised. With a chev V8, I can order from summit racing, a kit that will replace most of my components, and give me around 400HP out of the box. It includes new everything. The price of components for a I4 right now would scare people off this route, but if you talked to some local shops they may be able to give you some component lists, and mabye even give a quote.
Again because of the complexity of the dohc I4 engine, no one has really put out a serious non-race head setup for these engines either.
Ok in conclusion:
You are obviously debating the use of a NA system versus a turbo system are you not?
Here are some things:
1. A turbo system will allow you more power (done right) for less buck.
2. A turbo system however has drawbacks, allways using 92 octane gas, turbo lag, difficult street use, ect.
3. Notice how I have not mentioned nitrous? Well there is a good reason. Nitrous is not a fix all power added, it will require as much work as the others to get an engine that will last well on it.
3a.Nitrous also is illegal in some states on the road (yea not canada!)
3b.Nitrous is dangerous. It MAY explode in an accident. This has about the same change of happening as a propane explosion, so it is not really a factor.
It is really up to you and your budget. If you have some savvy, and experience (well not even much experience) bolting up a junkyard turbo is not that big of a feat. The ricers tend to think that is beneath them, where the krouts love the approach.
Of course both of these system will cost about 4000K.
You of course could do some minor things, and live with 180HP though... I have no clue what the B16 motor starts out as...
High boost means high pressure. Even if the turbo is within its limits, the rest of the engine may not be. If you're talking about using a D-series engine, much internal work will be needed to keep the connecting rods from collapsing. A B-series (especially the B18C from the Integra Type-R) will do far better, but when the boost gets above 1.0bar (14.7psi), the rigidity of the stock engine may not be enough. Hondas do well naturally aspirated (non-turbo), or with high-reaching VTEC. This is not to say that putting a Garret T66 on a properly prepared B18C5 isn't possible, but be prepared to put a lot of money into reinforcing the engine. Subaru is a good example of not fortifying vital components. After 3000 miles, I broke part of the transmission (the 1st gear synchro). I never raced it, never dropped the clutch...sure, I had some fun on the highway, but it was rather a short time to have something break. Turns out, lots of people had the same problem because Subaru transmissions are weak! 
