8.1 Muffler/ No Muffler

[yukon25008.1]

I got a mangnaflow #12599 dual 3" in dual 3" out, for my yukon 2500 8.1. I cut the old oem muffler out, and the truck isnt as loud as i thought it would be. It sounds good! so im thinking about just putting to straight pieces in place of the muffler.

my question is if there was Even the slightest power gain from either, what would it be the magnaflow replacing the oem muffler, or no muffler at all leaving the cats

[yukon25008.1]

Havent some of you 8.1 pickup guys run 3" all the way out with no cats?

[Riverjet502]

By chance you would happen to have a sound clip of your mangnaflow #12599 would you...????

[yukon25008.1]

Iget didnt even get it mounted, the truck sounds so good without a muffler, im undecided what im going to do

[Matt427]

I bet it's got a pretty sweet rumble goin' on! The only thing I would be concerned about is the resonance in the cabin while cruising at highway speeds. What sounds great around town can sometimes drive you crazy on the highway.

[yukon25008.1]

yea.. interior noise is the issue i have a 22 month and a 2 month old daughters, so sleepy time might be tough with no muffler, id just hate to put on the magnaflow and it be to quiet again

 

its almost worth trying with the 2 straight peices just to see.

[700 sportsman]

I haven't delt with and 8.1L's, but on with my 5.7L (350) I swapped out for a magnaflow, shorter than yours with a 5"X8" case, and you can definately tell it's there, but with yours being that much larger I be it will be pretty quiet. But I don't know if the 8.1's would make up the sound difference, but if you left it straight piped with a full tailpipe and stock exit points, it should be far enough away from the cab to have minimal drone, but like I said, I'm not sure about the 8.1L's.

[hockeypro1411]

I cut out the mufflers on my 6.0 to patch some small holes in them, and of course I HAD to see how it sounded without them. It sounded great, so I put some pieces of straight pipe in. Running the pips all the way to the back made it even louder. Literally the first trip I took I got pulled over when I pulled onto the main road and hammered the throttle. I told the cop my situation and that I was just playing with it and the welds were probably still hot yada yada yada and he told me to turn it around and get the mufflers back on. It was noisy, but living out in the middle of nowhere, nobody except the cops seem to care.

[yukon25008.1]

did you keep your cats?

with no muffler its definitly quieter than i thought it would be. still unsure what to do,

I think ill get a piece of 3" pipe and play and seewhat it sounds like before i go dickin with the muffler.

thanks for your help, let me know of anything else you think of, truck looks good by the way

[ws6_guy]

8.1L sounds awesome straight piped.

 

 

Not too loud compared to the 6.0L, but sounds wicked straight.

 

He used to have the Magnaflow you speak of.

 

[yukon25008.1]

Thank you for those sound clips, very helpful in making a decision

[yukon25008.1]

over the years ive been lucky removing cats without engine lights coming on, have you guys had the same luck removing cats from an 8,1, how did it work out

[Z'06]

over the years ive been lucky removing cats without engine lights coming on, have you guys had the same luck removing cats from an 8,1, how did it work out

 

You could always have your PCM tuned to disable the rear O2 sensors or, in the absence of tuning them out, install spark plug defoulers to trick them.

[yukon25008.1]

So your thinking id be ok removing cats,but if the was a problem i should put what? where?