Exhaust Pipe Diameter

[C_Root]

Quick question for those of higher knowledge, how does the diameter of the exhaust affect the exhaust note. I have heard a few sound clips, and most have been good, but I have noticed that the larger the pipe, the deeper the sound. Does this difference in diameter allow the sound to resonate within the pipe more, or something along those lines? Also, hands down, THE best I have heard was on a 04 4.0l, 3 inch pipe (!?) no cats, flowmaster delta 40. Sounded beastly. Any insight gentleman?
Thanks
Croot

 

[Sasquatch_Ryda]

The larger the pipe, the deeper the tone.

I have a highflow cat to 2 1/2" pipe to a Flowmaster Super44 muffler with a short 2 1/2" tail pipe that exits right behind the cab (comes up and over the frame rail) This is on my 91 4.0L.

Its is definitely loud....too loud almost. Thinking about making the tail pipe longer to get the noise away from the cab more.

 

[C_Root]

So then it really becomes a balance between how deep of a sound you want, but while still maintaining proper back pressure, 4 INCH PIPE ftw haha jk. So it seems that the standard is 2.25 to 2.5. Is it pretty well understood that 3 inch pipe would be detrimental to performance? thanks, i should be out of questions here pretty quick.
Croot

 

[Daniel_187]

Nah man put some stack on it 6 inchers will do JK

 

[C_Root]

OH YA!!! stacks for the win, HURL. Went to the muffler shop today and the guy there, and he knows his shit (been in the same shop for over 30 years), he was saying that a three inch pipe may sound great outside the vehicle but would be way to loud inside the cab. Also gave me a price quote on having dual exhaust done, 450 - 500 for si/do and out each side, sound about right?
thanks
Croot

 

[nate09]

ideally you dont want back pressure. what you want is a scavenging affect that draws the exhaust out of the system. i personally wouldnt go more than 2.5" its what i plan on using.

 

[sean9721]

450 - 500 for si/do and out each side, sound about right?
thanks
Croot

A shop around here charges about $250 for dual exhaust. I guess its different in your area.