Honda Car Forum

How much hp does new header and a new cat back give a 99 civic ex

most catbacks (such as HKS Hi-power exhaust) give around 10 to 15 hp gain. now add a cold air intake and some racing headers, and your looking at up to 25 hp gains. Then get everything dynoed and tuned and maybe you can get a few extra ponies out of that. up to 25 hp gains for under 1K? sounds good to me!

you would be very lucky to see 10 hp. The only way youre going to get any decent power out of a civic is via forced induction.

The first post was wrong to answer this we aren't adding HP we are freeing it from the restrictive Intake, Headers, Exhaust that Honda puts on theses cars. A good flowing Catback exhaust 2-5whp 7-10Crank, Header 3-4whp Crank 8HP. So you are looking at 5-9whp which would make your car about .01 tenth of a seconder faster next terms nothing. Unless you get a cam, itb etc etc etc. Going turbo and piercing a turbo kit could cost under $1500-2000 and net you 80+whp Or you can sell your motor for about $600 and get your self a B16, B18 etc swap

The first post is a gullable person that gets his knowledge from magazines and not test and trial. 25 hp from a intake, header, cat-back exaust is outrageous. You will be lucky like the previous post said to get 10hp from all 3 mods. I have driven civics with superchargers and they are not fast at all, so forced induction would be a waste of money unless you build your motor to handle a very high amount of boost. Fast fix would be nitrous (recommend 75 shots max on stock civic motor). Its not a full time mod but you get every bang out of your buck.

I'd say about 10hp...