triplenickle

Headin back to the plant today after the route, saw a 3d gen coming up on me pretty quick, actually looked like a PW, fender flares, big tires, red, ect. But OH no, this was big C! And it sounded awesome! It was loud (exhaust). I will admit, I know next to nothing about exhaust. What is it about a "free flowing" exhaust that can improve MPG and sound? Is it due to the fact that as the motor burns fuel, the "nasty stuff" that gets pushed out the rear can do so easily, thus freeing up back pressure on the motor? Is this the reason many guys like to remove the cat? (I dont need to, 04) Is that another reason that a exhaust system that is straight, with no bends, twists and turns is better for sound and MPG?

Stamey

An engine is essentially an air pump. If it can get air out quickly it can get air in quickly, and this means more efficient running (better MPG). Not that removing the muffler is going to give you a huge increase in mileage.
The truck you heard probably has had a mufflerectomy. I LIKE them.

Chris

smokey196240

Im running on my 06 dual stacks with cat sounds great loud when i get on it but nice when at hwy speed no muff.

Dieseljunkie

I know I really like the way my truck is setup.. Deleted the muffler, but kept the cat, with the rest of it being a factory 4" exhaust.. I love the throaty sound its got.
Scott

VikingDiesel

same here, love it, however, i still sometimes think i should remove the cat. But I do definetly love it right now,

04ctd

here is my strait piped 04:
the dark video (black screen) is a idle walk around.

yes, your basic assumptions are correct

http://04ctd.zippyvideos.com/

triplenickle

Thanks for the input. But what else is there for me to do? I have an 04, which means no cat converter already and a stock 4" exhaust. What's left to do? Remove the muffler and go with a "straight pipe"? Why are the 03s and 04s "cat less" and the 4.5s and up got a cat?

4x4not

I removed the muffler on my '05 but kept the kitty. I think it sounds great. Not too loud, but mean. I do get a little bit of a drone right at 1500rpms but I deal. It's not bad while unloaded but you notice it for sure when towing.

05mxdiesel

04.5 and up are 50 state legal and that is why they have cats. I am kittiless and str8 piped on mine. There is zero drone but my exahust is also 14 feet behind me. I have been considering stacks but I am happy with the way it sounds, but I still get jealous when I hear a 1st or 2nd gen str8 piped.