How much HP gain am I getting by adding a cold air intake, headers, exhaust system, and removing all my cats?

Question

I have an 02 civic.
Stock it is 120 HP. What is it now after I added all that?

Answer 1

I am guessing that with these mod's alone, you are probably putting out around 135HP.
It's not a very high gain for the amount of money spent. But all those mod's will help out a lot, and are necessary if you plan on turbo or supercharging it later.

Answer 2

Depends on whether or not you got a fart cannon or not. If you got a fart cannon that's bigger than 2.5" in diameter you probably lost backpressure and probably lost some backpressure; not a lot (without replacing the cat) but enough to lose low end horsepower to a degree (maybe 2hp). Cold air intake does nothing because most factory intakes are already cold air intakes (pull air from the wheel wells), if it's a short ram or the intake pulls in air that's hotter than the air the factory one pulled in, you'll also lose horsepower (throughout the power band). You might be pulling more air but if it's HOTTER the increase in airflow won't really matter. If it's colder and the flow is increased you might get a modest bump up top (2-3 horsepower over 4-5k rpm). I know that seems contradictory power-band wise but it is what it is. That's why you need to know what you're doing before you do it.

Answer 3

unless you port your intake and your exhaust, about 20 to 30 hp. with porting probably a total of around 60

Answer 4

First, removing all your cats is never a good idea for legal reasons. But all those modifications, you are prolly looking at between 15 and 20hp unless you drop a lot on parts, then maybe close to 30.

Answer 5

you'll probably get up to 30 hp total for all this, assuming you change nothing else, but this is a very rough estimate, it depends on the headers, intake etc...

Answer 6

I don't know, but if you run afoul of the law, removing the cats is a federal offense. Most federal offenses carry stiff fines and lots of jail time.