Has anyone gutted there stock muffler? I am planning on doing it i want to replace it anyway so the worst that can happen is a sound clip and a diy. So anyone done it yet?
If so did you just pull out the packing material or remove everything?

 

The worst can happen is it will sound like my buddies old 6 cyl Nova did back in the day. It had a hole in the muffler and earned the nickname "popcorn fart".

 

I figure i will pull out all the glass and if that dose not do much I'll open it back up and cut out the baffles pics and sound clips can be expected for the whole thing

 

Stock mufflers don't have any packing, it's all perforated tubes like a turbo muffler, only positioned for much worse flow and less noise.

Look at this:



You can see how restrictive it is and how the exhaust has to gothrough those tiny holes. This isn't a Blazer muffler but they're all this same style inside. I imagine you could cut some of the tubes open, point them in different directions, connect them so they flow better, whatever. Just use a cutting wheel to get the bottom off then once you've positioned and cut up the insides like you want, stitch weld it all up and weld it back together. I've been wanting to do this for a while but I always forget to keep my stock mufflers long enough to remember to try this.

Good luck and post pics of what you do.

 

The stock muffler on a Colorado dose have packing in it. But yeah i will take pics of every step and hopefully get a sound clip.

 

Magnaflows are `flow through style mufflers, if you gut your stock muffler and stitch up the piping like this it`ll definitely perform better. Also, I`d suggest packing it with some FMF Dirtbike pipe packing, the fact it`s flow through it`ll be aot louder. I have a maggie on my Sierra and its alot louder than stock, while not being annoying as sin or a cop magnet due to the packing. The issue with packing is eventually it will wear out on you and get REALLY loud... a friend of mine has a 12 year old Maggie Catback on his Ram with headers, and it might as well be straight piped.

The issue with chambered mufflers (and yes, Flowmasters are chambered) is they restrict flow, I don`t care what the pencil pushers at Flowmaster say. Loud does not always equal power.

 

That is exactly what i wanted to do oktain. And i agree about chambered mufflers

 

I didn't know that about the Colorado, makes sense though since they're cheaply made. Packing does burn out, even the stainless steel wool used in modern Magnaflows will burn out. I have a Thunderbolt highflow cat (as loud as a Dynomax Bullet) and a 3" in/2.5" dual out Magnaflow on my Sierra and it dumps out the side in front if the axle, this is my truck, ignore the dent:



The muffler is the 18" case, and it's super loud. It's just as loud if not louder than a Flowmaster 40 now, not near as much drone but just as loud with the highflow cat. It's so loud now that i'm getting tails and putting the tips back like this:



Now on my Suburban I have an 18" case 2.25" dual/2.5" single out welded in the stock pipes:



Stock tailpipe, bend cut off which eliminated all drone:



And it has gotten a bit louder over time but not loud by any means, not like the Sierra at all.

I'd love to see how it looks and sounds when it's done, if you can plumb the insides like a Magnaflow or a little better than the average turbo muffler, it'll be well worth it.

 

Yeah ill have to open it up and see what there is to deal with. And more the a few manufacturermanufacturers are packing there mufflers now. Some caddys are packed as we as bmws

 

Yes flowmasters or any other chambered muffler dont have nearly as much flow as a straight through muffler or straight pipes but they absolutely have more flow than a stock muffler as shown above.