How can I make my 06 civic si fast, with out turbo,supercharge and nos?

ok well first of all you could swap out the headers with a one piece 4-1 header. upgrade your alternator to a racing alternator. it just puts out more amps and watts etc. aftermarket intake manifold, cold air intake. a short ram will react quicker seeing as how the piping is more straight and not as long, but a full cold air will pull more cleaner, not as hot air from the bottom of ur car rather than hot dirty air from inside your engine bay. then you could do a header back exhaust with a performance catalytic converter. i would say 2 1/2 inches or 2 3/4 inches all the way back. you could get bigger cams, better fuel rail, bigger hoses. but if you do cams, your gonna have to change a bunch of stuff that goes along with that. u could port and polish your head. pistons, rods...all internals basically. u could chip your ECU. then if thats not enough you can make your car lighter, which obviously wont increase your HP, but it will make ur car lighter, which will result in being faster. examples would be taking our your power steering pump and your air conditioner. those are made out of a heavy metal, you would probably loose a good 30-60 pounds right there. all front end wieght lifted. carbon fiber hood, side mirrors. you could go to the extreme and get a carbon fiber body kit (oem or after market). lighter rims. carbon fiber trunk. plexiglass windows. fiberglass doors and fenders. lightweight front seats, take out the back seats. empty the trunk of the spare tire, jacks, carpet, anything else in it. i mean thats gonna put you as probably one of the fastest SI's if you were to do all that. just little things. tips and tricks. hope this helps

aftermarket exhaust?

well if you dont wanna go f/i you gonna want to do. high comp. pistons and biggers cams!

umm....there isn't much, besides headwork, cams, ecu work and bolt ons. but then your still going to be spending alot of money and would still get beat by a civic si with FI kit. Or...you can swap in a motor. That isn't any cheaper either.

You are going to have to spent alot of money to modify the engine. If you want to make big power with a smaller engine you really have to have a power adder of some kind. If you don't want to use one, the car will never be "fast"... not unless you compltely re-do the motor and strip the car down totally to reduce weight. You are looking at ALOT of money.

Buy: Intake, Headers, exhaust, Iridium spark plugs, 10mm spark plug wires, lighter wheels, take out passanger and back seat, get the head rebuild at the shop and have them open up the valves making them open wider for more of a kick, vtec controller, drop the front lower then the rear, take out power steering and AC. your looking at maybe 300HP and like mid 13's at the track.

Carbon fiber parts. Take out other parts which is not needed. Fastest and cheapest way. Or you can always just step on the gas. :P!!!!!!!

add cold air intake, new exhaust, spoiler