Sound difference: 3" vs. 4" vs. 5" vs. 6" vs. stacks?

[GO 4LO]

Not having been around Cummins trucks that long, I was wondering what the differences are, in terms of sound, between 3", 4", 5", and 6" exhausts, and also compared to stacks? I met a guy at the gas station today who had a 4" exhaust with muffler that sounded much deeper than my stocker straightpiped does, but about the same decibel-wise. So how do they all compare, tonewise and decibel-wise?

(I'm not concerned with how much power they make or how much power I should be pushing before needing X-inch exhaust, just sound. ) Thanks!

Chris

 

[Tcolesanti]

From what I know, the bigger diameter, the deeper it is, the smaller the diameter, the raspier it sounds. Any of the staight through mufflers cut down on the raspiness of any straight pipe and give a cleaner (more politically correct) exhaust note. I for one have never, ever, even considered putting a muffler on my truck. Just my $0. 02

 

[tURBOdIEZEl]

go 4 lo, here is a video of my truck driving by the camera running thru about 3 or 4 gears! in my personal opinion, the smaller the stack is the crackier and poppier it is when you really get down on the throttle. just my . 02!

 

[NPloysa]

I have a stock straight pipe. It is a little raspy but I am use to it. I am going to go to a 5" straight through system and may or may not be pleasantly surprised. I do know that most people with 5" straight through are happy!

 

[nickleinonen]

go 4 lo, here is a video of my truck driving by the camera running thru about 3 or 4 gears! in my personal opinion, the smaller the stack is the crackier and poppier it is when you really get down on the throttle. just my . 02!

that clip sounds awsome... .

 

[GO 4LO]

Thanks for all the input, everyone. TurboDiezel, I'll have to watch that clip when I get home, as I can't get it from this computer. Thanks!

Chris

 

[RCCola]

Great Video, make me know I NEED stacks.

thanks

 

[Tcolesanti]

I too am convinced I need an aluminum flatbed with STACKS!!!!!

 

[tURBOdIEZEl]

that clip sounds awsome... .

thanks. had a buddy of mine record that this past weekend, i wanted to see for myself how much smoke pours out of my stacks since my new bombs!!! :-laf

 

[jwdeeming]

There's a white 2nd gen shortbed running around Longmont with stacks. It's too much bling for me to do but boy does it sound COOL!

 

[bmoeller]

I too am convinced I need an aluminum flatbed with STACKS!!!!!

I did just that. You won't be disappointed at all.

 

[nickleinonen]

thanks. had a buddy of mine record that this past weekend, i wanted to see for myself how much smoke pours out of my stacks since my new bombs!!!

i need to find someone who's got a DV cam to make a clip of my truck... i think it sounds good [especially when the turbo winds up] but i would like to share it too...

 

[kentdiesel]

After having the stock exhaust system, a 4" system and now a 5" exhuast system I have to say the 5" sounds the best. The bigger the pipe, the deeper the sound.



My current 5" exhaust has a 51" long straight thru Donaldson muffler and still has noticeable sound.

Example: I let my wife out at the Grocery Store and she says after the sliding doors close and I start off, people in the store are looking up wondering if a truck is coming thru the building. This has happened on multiple occasions. It's not a ear pericing loud, just a deep sound that carries. The visual impact the 5" tailpipe has gets few comments also.

It's a Rip Rook system and even with a 285 size spare tire the tailpipe fit fine.



I haven't had stacks but I have heard trucks with them and they have deep sound that carries.



You probably don't need a 5" exhaust until your in the 500 plus hp range but it still makes a low hp truck like mine sound "mean".

Kent

 

[NIsaacs]

4" seems to be a good all around size, sound, looks, ease of install and cost. The sooner you go to the larger size pipe the better they sound. On my Ford CTD, I went with 4" from the down pipe all the way to the 6' stacks, it sounds just like a big truck Be sure you use the tee with the split entry. It will improve on the exhaust pulse and make the timing of the smoke match. Without it, the short side will smoke first, then the long side, looks goofy. Having said this, any size twin stack looks and sounds better than single exhaust. I would stay away from the 3", from a distance they look too small for the rest of the truck.





"NICK"

 

[NPloysa]

I stopped at the grocery store one day, went down the aisle right in front of the main doors, going away from the building. My exhaust ended up being right next to a lady that was walking down the opposite side of the aisle (No, I did not smoke her and I was going slow). I parked opposite her, and when I got out and was walking toward the store, she says, "Excuse me, can I ask you a question?" I said sure. She says, "Why does your truck sound like a big rig?"

I told her it was because I did not have a muffler. She looked puzzled and said, "Oh, thanks. "



If I get those compliments/questions on straight stock exhaust, I can't wait til I go to 5"!