
Originally Posted by
D16Civic
You will notice a slight power gain, but not a ton. I'd say a 5 whp gain at most, if even that much. If you don't really want your car to be louder and are not after the sound of a nice exhaust then i wouldn't do it. If you're planing on doing other upgrades (turbo, etc...) later and are gonna want to make more power, then yes, its kind of a must.
If you want an exhaust that sounds good (a nice deep tone, not like a freaking bumble bee) and is not overly loud, look into a Greddy Evo exhaust (2.5 in). Thats what i have on my civic with a d16y8 in it. One of the best sounding exhausts i've heard on a civic and a lot quieter than most aftermarket exhausts. Kinda pricey though, a custom 2.5 in. probably cost you less.