l have a 2002 4 clylinder Accord coupe. (l know, not the ideal wrx sti) But...that aside, if l were to drop the money on headers air intake etc etc...what would my maximum hp output be? would it even be worth it? would l even notice a difference? could l reach 250 hp w/o hurting my car? how much money are we talking here? could you list some specific products l can look at?
thanks

Cold air intake, maybe a couple hundred, and might net you a few horsepower. Exhaust system, headers, and computer reprogram or new chip, maybe a grand or a little more, and you might see 10-15 horsepower. You could tear down the engine, buy forged internals, port the heads, and buy a turbo and the above mods, intercooler, etc. In that case you MIGHT hit 250 horsepower, but you are looking at several thousand dollars.
A V6 swap would be much better.

Push it off a cliff, you will get terminal velocity.

save ur money for ur next car, & plan on fixing that up.. lower miles, better baseline for modding.. happier person.. ur gonna have to spend so much money to get what u could get now a days stock. but if u have to go fast.. look at the mileage? is it in the condition to take a hp increase.. if so. intake, exhaust, header, suspension, brakes, weight reduction ( cheap hp ), ignition stuff ( plugs, wires ), better intake manifold, lighter wheels, turbo of course, then u need the intercooler, better fuel delivery, prob make a kit for all that.. then u have to look at internals..also new exhaust for the turbo.. new intake for the turbo.

i would take all the money u would spend & save it for another car.. dont make do with what u got.. wait & fix up what u want

Lol, the k24a4 engine is a bitch to mod,

with intake headers and exhaust you probably will only gain 10hp

to get to 250 natural aspirated there are many ways but it is difficult
and to get to 250 with forced induction is pretty simple..

but in the long run its going to be couple grand.