I have a 96 civic ex coupe with the d16y8, with 93k miles now. The only engine mod is an AEM SRI, and I was thinking of doing the header, and exhaust for some more power and mpg. How much would the i/h/e give me? Im guessing around 10 whp or so? How much MPG increase would I see?

I live in cali, so it has to be legal. I was thinking of getting a DC Sports 421 ceramic 1 piece header. SO the 421 gives me low end power right? Whats the difference between the ceramic and stainless? SHould I go for 1 piece of 2?

Any other legal headers?

Now as for the catback, I was thinking of getting a custom one, but im not sure if that would be legal in cali. What kind of piping, size, muffler, and etc would I want. Is there any difference in power from a custom one, and an aftermarket one?

 

IHE together will not give you much HP...maybe 5..up to 10 at the wheels. what it will give you is better throttle response, which will feel like added power.

i dont remember who it was...maybe forty04....but someone was saying their y8 was seeing 40 something miles to the gallon with just an intake and exhaust.

at stock levels, the feel between 4-2-1 and 4-1 will be of minimal difference if any. ceramic headers keep heat in better than stainless..but i believe stainless are lighter than ceramics (someone else can confirm or deny). 2 piece headers are easier to install...but i'd go for a one piece, on the theory of 'less parts there are the less there is to go wrong'.

most quality parts are carb exempt. DC sports, megan racing...stuff like that. im not sure about anything else but i know DC sports has a 'CARB Exempt' plate welded on their headers where you can see it.

making a custom catback would be legal as long as you're running through a good cat. piping wise, you would probably want 2.25", stainless steel, and you could get a good quality muffler off of ebay. Greddy, Magnaflow...you can find mufflers by themselves to stick on the end of custom piping..and you basicaly have a $450 catback for less than half that. power difference is minimal...but make sure when you get your piping made they use a mandrel bender, not a crush bender. all good aftermarket exhaust are mandrel bent.

 

1 piece headers are lighter than 2. Stainless are lighter than ceramic, but for a street car ceramic are the way to go, as the coating will keep exhaust temps down over extended use and extend the life of the header itself. I would prefer a 4-2-1 on the street, as it gives gains over a broader power band than 4-1, and provides better ground clearance than a 4-1. 4-1 is for soley top end gains.

As for exhaust, I'll always recommend custom piping and a universal muffler if you have an inexpensive and dependable shop that can make it for you. It's cheaper and does the same job. Just make sure you get mandrel bends and not crush bent.

 

just stay away from the 4 into 1 header.. tryed and i would play catch up with just about everyone....and not to menchion i have an import mag that test a bunch of headers and the jdm american speck was the best

 

yeah that was me. AEM CAI and Megan Racing cat-back, showed average of 38.6mpg, even with me taking third gear rips on the two lane highways to pass people. I think the best it showed was 40.3 or something like that.

 

so far i havent noticed any gains from my header or intake. tho my header is cheap and so is my intake.LOL

it feels alittle more snappy.... but with a automatic tranny well enough said......
for a manual it would probably realy be noticable! but when i stomp it it just revs up kinda slow. BUT o well i bought this car for more MPG than HP...... and so far its doing a great job!

 

Thanks for the replies guys. ANy recommendations on quiet mufflers and piping?

 

From what I can tell most mufflers sound good so long as you have a resonator installed in the piping. They might not be quiet though, but they'll at least be deep and not raspy. Twin loop mufflers are ultra quiet, but I just don't think they preform as well as straight through designs.