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Discussion Starter · #1 ·
hey all
i got civic 1.6i.16 (EDM D16A9).

originally it comes with exhaust that has two mufflers in middle (resonators?) and regular rear one with two exits, and it has no catalyst from factory.

Im interested in making custom exhaust at my local shop. So I need advices from all you experts out there :)

I'm interested mostly in gaining more power (not loosing any at all from stock ! :D ). Engine itself is going to be with stock internals, and I will buy just basic Ebay header 4-2-1 and some SRI intake, mostly that will be it for now as far as tuning engine goes.

first, what's stock inner tube diameter ? And how far away from that should i go ?

What about mufflers ? Is it necessary to make two in middle like original, or just one is enough ? If just one, does it need to be longer than original? Larger diameter, smaller? How to make them ?

I need some thoughts on this.. -As far as loudness goes, i dont mind exhaust being louder than stock, but it's going to be everyday car so race db levels are not wanted for now.

Pls, keep in mind, i'd like to keep original engine torque through whole range (dont mind being higher somewhere) and not to loose any - and 1,2,3 additional HP is of course welcome too.

So, how to make whole exhaust ? piping, diameters, mufflers .... your turn guys, need some help :greddy:
 

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Wagovan
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I wouldnt run larger piping than 2" maybe 2.25" with a larger camshaft. One resonator, what you refer to as the mufflers in the middle will deepen the tone and quiet bing bing angry bee noise. That paired with a sport muffler or small canister type muffler at the end of 3" outlet looks nice and isnt too loud. Magnaflow resonators sound awesome.
 

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Since i have almost the same engine (D16A8 ), i may be able to help you.

Question: Will you be changing the headers/exhaust manifold? Keep in mind that the biggest constraint in the stock exhaust is the part that connects the exhaust manifold to the cat. Of course you dont have a cat, but i assume this part is the same with D16A8's. So, your stock exhaust has a 48 mm EXTERNAL) diameter (45 mm internal), but this part after the manifold is "double", like a second pipe inside the first. So despite that from the outside it seems to be 48mm, internally it's 38mm. Bottom line, get rid of it.

I would suggest a 2.25" pipe from the exhaust manifold until the muffler. With one extra resonator to keep it quiet. You should be ok with this, both in low-end and high-end rpm range. If later you buy a 4-2-1 or 4-1 header, buy a 2.25" one.
 

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Discussion Starter · #4 ·
thx for advice Save/Sohc, one question, should I worry about lenght and external size of middle muffler? What would be optimal for torque+power ?

i-vtec
thanks, I understand what you are saying :) How could they produce it such way? :( makes no sense.. Yes I will buy aftermarket manifold, and internal exit size will be 2" - 2.25" (still haven't decided), btw those stock measures I was looking for .. ty :)

So final question would be, 2" inner diameter piping (manifold) vs 2.25" on stock motor with only intake?

cheers everyone
 

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I think many stock car exhausts are like this...Probably to warm up the cat faster when you cold start the car...double pipe= less heat to the environment=more heat to the cat.

I vote for 2.25" header and 2.25" exhaust pipe.

P.S. Please rep me if you can:biggrin:
 

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I would look into a dynomax turbo muffler, actually pretty quiet, until you go WOT. Best part is that they are like $40-$50. I personally run one with just a Canister race muffler as a resonator and is pretty quiet when cruising but when I want to go it screams. Also make sure you use mandrel bent exhaust piping and not that crappy crush bent that alot of muffler shops use.
 
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