Loud exhaust/header combination

[Alltezza]

Catless UEL headers and an Invidia N1 Catback (;

I love it, but if I could go back I'd probably go with a Tomei catback for weight reduction and just to make it a little louder. Type 80 Tomei if you REALLY wanna be loud or going turbo.

[go_a_way1]

^ type 80R is loud as F in person even just the catback itself

[pandamancer]

Run any catless header and an over pipe only. Forget the rest of the exhaust if your only concern is to be loud.

You won't be legal(volume or emissions) and will probably make less power on an NA motor(no back pressure) but you will be extremely loud.

[jawn]

Originally Posted by pandamancer

Run any catless header and an over pipe only. Forget the rest of the exhaust if your only concern is to be loud.

Citations needed.

There are tons of folks on the forum running only catless headers + tune without a "back pressure" problem.

Also, back pressure isn't a thing. Exhaust velocity and scavenging is.

[whataboutbob]

I've ran a Tomei EL with an Invidia catted front pipe with a 60r and a sprintex 210 blower. It was loud, too loud for me.

[ZOMFGAARON]

Straight pipes the answer.


Sent from my iPhone using Tapatalk

[pandamancer]

Originally Posted by jawn

Citations needed.

There are tons of folks on the forum running only catless headers + tune without a "back pressure" problem.

Also, back pressure isn't a thing. Exhaust velocity and scavenging is.

Citations not needed... If you remove all the piping, you will be as loud as possible without explicitly designing an exhaust system to be louder(though I think even that is not factual as restrictions reduce flow which in turn reduces sound, and ANY exhaust piping is a restriction as compared to NO exhaust piping).

I also did not say there would be a problem, just that you may make less power.

Further, back pressure is in fact a thing(phenomenon really). Back pressure is a resistance to the flow of a liquid, in a fluid dynamics sense, due to restrictions in the evacuation path. It does have an effect on exhaust gas velocity and scavenging, which is why it is a useful mechanism for engines. Anybody that has tuned a two stroke engine probably knows that you can affect the power output(both peak and AUC) by tweaking the exhaust due to this very phenomenon. A little back pressure in the exhaust can actually improve the intake and net you more power.

Edit:
After reading my own post, I should qualify my volume statements to include "over a wide frequency band", as you could certainly tune an exhaust to be louder in a small frequency range.

[jawn]

Originally Posted by pandamancer

Citations not needed... If you remove all the piping, you will be as loud as possible without explicitly designing an exhaust system to be louder(though I think even that is not factual as restrictions reduce flow which in turn reduces sound, and ANY exhaust piping is a restriction as compared to NO exhaust piping).

I also did not say there would be a problem, just that you may make less power.

Further, back pressure is in fact a thing(phenomenon really). Back pressure is a resistance to the flow of a liquid, in a fluid dynamics sense, due to restrictions in the evacuation path. It does have an effect on exhaust gas velocity and scavenging, which is why it is a useful mechanism for engines. Anybody that has tuned a two stroke engine probably knows that you can affect the power output(both peak and AUC) by tweaking the exhaust due to this very phenomenon. A little back pressure in the exhaust can actually improve the intake and net you more power.

I think we may have gotten our wires crossed - when you said "catless headers and overpipe only" are you inferring to removing the plumbing after that? I'm referring to running catless headers + stock everything else.

I'm not going to contest that having piping will improve flow, but back pressure is too often used as an excuse for having the wrong diameter piping for a given system: obviously, going with huge piping or no piping will decrease velocity. You want fluid velocity to be high, and the easiest way to manipulate that is to manipulate cross-sectional area. Bernoulli's principle dictates that a higher velocity fluid is lower pressure.



Also, 2-strokes are an entirely different animal, since you need to time the velocity of the burning gas/air mixture, so you're not blowing it out of the exhaust before combustion has finished. On a 4-stroke, you want it to scavenge as quickly as possible, since combustion has completed on the exhaust stroke.

[Cole]

Just curious as to why you want your car to be obnoxiously loud.

Do you intend on tracking it? Well, a lot of tracks/events have noise limits, so you won't be allowed on track.

Do you want attention? It'll be fun when you're getting pulled over every day and having your neighbours hate you every time you leave the house.

Any way you slice it, if you have to do drives of any length over 10 minutes, you're going to be blessed with ears that are always sore as fuck plus you'll look like a massive fuck boy every time you drive the car.

I'm going to guess that you're young and give you some advice. I did the stupid loud car thing and it's not fun after the first day, and you're going to spend twice the amount of money on exhausts than you should have because you'll very quickly be wanting something that isn't quite so stupid.

[pandamancer]

Originally Posted by jawn

I think we may have gotten our wires crossed - when you said "catless headers and overpipe only" are you inferring to removing the plumbing after that? I'm referring to running catless headers + stock everything else.

I'm not going to contest that having piping will improve flow, but back pressure is too often used as an excuse for having the wrong diameter piping for a given system: obviously, going with huge piping or no piping will decrease velocity. You want fluid velocity to be high, and the easiest way to manipulate that is to manipulate cross-sectional area. Bernoulli's principle dictates that a higher velocity fluid is lower pressure.



Also, 2-strokes are an entirely different animal, since you need to time the velocity of the burning gas/air mixture, so you're not blowing it out of the exhaust before combustion has finished. On a 4-stroke, you want it to scavenge as quickly as possible, since combustion has completed on the exhaust stroke.

I mean just what I said, catless header and over pipe ONLY. Though, some headers go 4-2 and rely on the overpipe for the 2-1 while others go 4-1 so you could even remove the overpipe in some cases while still retaining a unified exhaust system across all cylinders.

2-strokes and 4-strokes are both Otto cycle engines and so aren't entirely different, though for the purposes of scavenging you are mostly correct. I say mostly because even with 4-stroke engines, there are some cases where exhaust and intake overlap allow for back pressure(or lack thereof) to affect the performance characteristics of the engine. I used the 2-stroke example as a case study on back pressure being a real and usable phenomenon.

But we both digress, the OP wants loud, not performant. I think we both agree that loud comes from minimal restriction.

[aneesrehman]

I guess my real question now is which exhaust/header setup is not necessarily the loudest overall, but has the loudest typical boxer "rumble" or, in other words, sounds closest to an sti

[jawn]

Originally Posted by aneesrehman

I guess my real question now is which exhaust/header setup is not necessarily the loudest overall, but has the loudest typical boxer "rumble" or, in other words, sounds closest to an sti

Any UEL header + any loud catback.

[Cole]

Originally Posted by aneesrehman

I guess my real question now is which exhaust/header setup is not necessarily the loudest overall, but has the loudest typical boxer "rumble" or, in other words, sounds closest to an sti

Since you've provided basically no additional information about price range, goals, etc. other than the fact you want to be loud. Get any UEL non-catted header. Pair with a non-resonated, non-catted front pipe and find an exhaust without any muffler or resonator. Then, you'll have the ultimate obnoxious, cop-baiting, neighbour hating car on the face of the earth and you'll have achieved your goal.

[rawafoo]

Tomei UEL headers , N1 Catback and any overpipe and frontpipe combo ��