whats the differance between short ram air intake and cold air intake?
Ram air has a scoop of some kind mounted to collect fast moving air from in front of the car, and ram it into the intake. Some systems can give power gains similar to a small turbo. A cold air kit just allows cooler air from outside the engine bay to be drawn into the intake system. Cold air can be added with no modifications to the sheet metal, but a ram air system will most likely involve body work.
02accent,
You seem to be asking quite a few questions on the boards about engine performance and engine performance parts. There’s a lot of information that really needs to be covered that goes beyond the basic questions you’re bringing up. You might want to head over to Barnes & Noble or Borders and pick up a couple of books that cover everything from A-Z. We could spend hours just discussing one aspect of the motor and its impact on the other parts.
Based on your other post, if you’re looking for very noticeable horsepower you’re not going to get it cheap. Cold air kits, catback exhausts, etc. are going to accomplish very little and are not really worth the cost.
You want power then you’re going to need camshaft/cylinder head work, Nitrous (kind of an expensive pain and potentially engine wrecking), or forced induction (turbo or supercharger). Forced induction often leads to more expense on the peripherals and if not done correctly can also be engine wrecking.
The old adage “speed costs money, how fast do you want to go” always applies.
amen.
Here’s another adage:
Cheap / Fast / Reliable <–does not exist. Pick any two.
A circa 1988 5.0L Mustang says hi. Cheap, check… Fast, check … reliable… check. 
But, would that apply to an '02 Hyundai Accent after the engine is tweaked beyond its design parameters? Very doubtful, IMHO.
Cheap / Fast / Reliable <–does not exist. Pick any two.
My experience says you can pick any ONE of those. 
More speed = more $$$ = more frequent repairs = more money.
The thing about adding some serious HP to a Hyundai Accent (other than why) is that the weak link in the chain is always going to be present.
Add 75 HP to an Accent and see how long the transaxle and halfshafts hold up.
Want reliable go-fast then it’s a Fox body Mustang with the 5.0. Readily available, will take a beating, and these cars run pretty quick even in stock form. Even a 3rd or 4th gen Camaro would do the trick since even the 4th gen V-6 cars have 200 HP.
not to mention the rod flying through the bottom,out the block ,bounce back,and blow through the hood.
never the less a great conversation. buy a really good helmet.
GOOD LUCK!