Headers vs. Exhaust Over time

[PrinceMiro]

So when I first installed my exhaust, I was told it would sound better as time progressed. I forget why, but it was true. The exhaust note improved as time progressed.

I recently had headers installed. They sounded alright, but not great. I took the car for a long drive last night and, by the end of the drive, the car sounded amazing.

So my question is: Does the same rule apply to headers? Also, can someone explain why the sound improves on the exhaust and (if applicable) the headers? Thanks!

[Kgolf31]

Exhaust improves because of carbon build-up within the muffler.


I would imagine, on a cold-start engine with headers the exhaust is not warmed up and therefore exhaust note not desirable. With or without headers this would be the same.

Once your exhaust gets to temp, sound does improve. Whenever I start my car the exhaust is loud and drones, give it 10 minutes and once it is nice and warm it sounds much nicer.

Make sense?

[GriffBrew]

I always assumed it was just as people got used to the sound, they thought it was different, even though its not. So I'll be interested in the science behind this

[PrinceMiro]

Originally Posted by Kgolf31

Exhaust improves because of carbon build-up within the muffler.


I would imagine, on a cold-start engine with headers the exhaust is not warmed up and therefore exhaust note not desirable. With or without headers this would be the same.

Once your exhaust gets to temp, sound does improve. Whenever I start my car the exhaust is loud and drones, give it 10 minutes and once it is nice and warm it sounds much nicer.

Make sense?

Yes. The carbon buildup in the exhaust rings a bell now that you mention it. Good to know with the headers. So it's solely based on temperature? Nothing else?

Originally Posted by GriffBrew

I always assumed it was just as people got used to the sound, they thought it was different, even though its not. So I'll be interested in the science behind this

[gferil]

I think it depends on packing material/method of muffling within the muffler...supposedly some of it gets built up with more carbon and/or some of it burns away so it will change the exhaust note over time. Not sure if that affects headers since all they are is metal tubes, but I can say that my system is more raspy when cold compared to when it warms up.

[Kgolf31]

Originally Posted by PrinceMiro

Yes. The carbon buildup in the exhaust rings a bell now that you mention it. Good to know with the headers. So it's solely based on temperature? Nothing else?

It more-so needs to do with the exhaust.

If you start-up your exhaust...notice how it will be loud, annoying, and want to explode your head at idle.

Wait a minute or 2, and it should quiet down.

Once the muffler heats up, it gets to "design properties", I guess that's the best way to put it. That is how it muffles and shapes the sound the best.

You know how if you try to rev your engine when it is cold it sounds like a chainsaw, but if you do it when it's warm it sounds completely different? All dependent on the muffler temp...and probably some other minor factors.

[ZStig]

Also, a warm exhaust will close down any small leaks in the connection points, as the metal expands. Most noticeable with electric cutouts