Exhaust pipe diameter vs loudness.
 

Yes, I've searched. :p:

I bought another FC and recently had to take its stock exhaust off to change the clutch. My gawd! I'd forgotten how spoiled I was after putting a single exhaust on my other FC. :doh:

So the new FC is going to get a single soon, too. I just have to decided on what pipe diameter to get. The piping on my 'old' FC is 2.5" with a pre-silencer and can, and it is damn loud. I'm wondering if I reel the 'new' FC's pipe in to a 2" maybe it'll bring that noise down a bit, which I would prefer.

My guess is that noise damping ultimately comes down to what kind of pre-silencer and muffler I use and that the pipe diameter won't have too much noticeable impact. But then that's a guess. :)

Any informed opinions out there?


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as far as my experience goes, you are right about the presilencer - muffler combination dictaing how loud your exhaust is. pipe dia will dictate the flow characteristics/ backpressure, and the tone of your exhaust note. by tone i mean the musical tone. the larger the pipe dia the lower the tone. the smaller the pipe the higher the tone.

hope that helps,
TR

My 3" is quieter than most 2.5" systems. Good mufflers make a huge difference. Not something that is called a muffler by some name brand....but an actual one. I use a Borla XR1 where the cat usually goes, and a Apex'i N1 at the muffler end.

I have hard that if you run single, it will be louder than dual also.

Run dual then and dual looks a hell of alot cooler. I just have a downpipe and a borla cat and the factory mufflers coming out that back and it sounds real nice and its 2.5

Well if the diameter of the pipe is bigger it should have a more deeper resonating sound than a 2.5" opening. If the diameter is decreasing towards the tip, the exhaust velocity should increase and im assuming should be quieter.

If the diameter is increasing the exhaust velocity will slow down and have more time to resonate at a lower frequencey in the muffler making it sound louder.

Jason NYC

Nope. I have my heart set on a single. Less weight and less of a pita to instal and remove. As for the look, the tip of the Sebring muffler I have on the 'old' FC looks pretty good just barely sticking out of the back. But then we milled the bumper to match it. :)

Good points about diameter affecting pitch - I should have realized that. So I can go 2" and while it may still be loud, the rumble may not reach as far... As long as it doesn't sound lame or weak, I'll take it. :)

I think 2" may be a bit too small... would sound like a civic with a 'universal muffler' on it

yeah 2" might be a lil small i would stick with the 2.5"

Exhaust wall thickness also has an effect. Thicker wall exhaust tubing may be harder to find and weigh more but makes a quieter exhaust.

Like Racing beat

I have personally run 2-1/2" straight pipes on my car. It sounds very cool, but will make you go deaf. A higher pitched sound will have much more of a sharp, raspy sound...more like a weed-eater. That sound drives straight into your brain like a nail into your ear.

Being stock and N/A, I cannot tell any real performance difference between strait pipes and my current setup.

Right now I have a 2-1/2 bonez highflow pipe with a pesilencer, a high-capacity cat and dual 14" turbo mufflers. The sound is deep and rumbly. It is NOT loud but I get lots of complements on the nice deep sound. The sound is not nearly as loud as the fartcan civics and eclipses that are around. Last year I took the cat off after emissions. The sound was a little louder, but just as deep. This year the cat is staying on and I am satisfied with the sound.

The pipe diameter may influence the pitch, as in higher or lower somewhat, but that is not the same as volume. I may be wrong, but I would bet that the quality and type of muffler has more to do with the pitch and the volume than the diameter of the pipe.

if you're going single all the way, i would advise you to run 2 1/2" all the way back with a high flow cat or borla, magnaflow presilencer to a twin loop muffler. this type of muffler runs the exhaust pipe through the muffler twice to reduce noise but only marginally hinder the flow charactoristics of a 2 1/2" exhaust.

that should do you just fine. good flow low noise mid range tone.

TR

pipe dia is the easiest way to dictate pitch. what you really need to do is increase the volume of the pipe to slow down the air and sound traveling through it. the thickness of the pipe also plays a part in tone and volume. the thicker the pipe the less it will vibrate. this will send more of a crisp tone out the tip. the thinner the pipe, the more it will vibrate and dissapate the sound through the the system.

TR

Sounds logical to me; A thicker wall will also reduce the tendency of the pipe to resonate and pickup annoying buzzes. Careful hanger placement helps too.