Anyone:

I read a post from March where a guy removed his stock muffler from a 05 duramax, left his cat on, and went to a straight pipe. He stated that the cat kept the tone of the straight pipe OK. I am thinking of doing the same, but the only experience I have had with straight pipes is on gas burners. Definitely don't want that sound from my 05 duramax. Anyone else out there tried this fairly inexpensive way to open up the exhaust system??? Will the sound be much louder than stock or maybe a flowmaster without the cat???? I have opened up my air intake as suggested on several posts and want to open up the exhaust end now. Any info would be appreciated. I have tried to contact the guy from the March post with no luck.

Hooky

I deleted the muffler on my 03 and kept the factory pipe. but it doesn't have a cat. The sound it makes to me sounds like my 99 crew cab that had a 454 in it with a dual stock pipes and flowmaster sereies 50 muffler with 4 inch magna flow bells on itnot really loud until you stand on it

Thanks for the reply. Any others out there???

I have a 05 6 speed and I removed the muffler to find out it was not any louder. The I removed the cat, and ran 4" out in front of back wheel still not very loud. mostly all you here is the charger. (dose not have a powerstroke sound

if you only remove the muffler it does not get much louder. you have to remove the cat to get "some" noise.

Mine was pretty quiet just with the muffler gone. Removing both made it louder, but still not all that loud.

here is a video of nar's truck with the straight pipe
http://users.adelphia.net/~raven0826/MOV00091.MPG

i just got an 05 duramax and the first thing i did was delete the cat and the muffler, it made the turbo louder and the exhaust is not loud at all but it does sound alot better

I did the same to 04.5 but just took off the muffer little loader when starting up. have a goon at 1800 rpm now. DO IT RIGHT THE FIRST TIME.

i should learn how too spell "groan"

For those of you who are having the muffler cut out by a local shop, are you having them drop a 3" piece in?

All the muffler shops around here say they cannot do a 3.5" pipe, which is what the stock exhaust is.

They sell a 3.5" piece on Ebay.I picked up a piece of flexible at a scrap yard.It sounds nice but I would like it louder. It's not nearly as loud as my 97 2500 454 with dual strait pipes):h was though.

Has anyone upgraded to a 4" exhaust (including the muffler) and replaced the kitty with a test pipe? What's That sound like?

Ed

here is a video of nar's truck with the straight pipe
http://users.adelphia.net/~raven0826/MOV00091.MPG

Kinda hard to hear over the other truck's exhaust... Anyone have some better audio of a straight pipe set-up?

I Got The Cool Duels From Mbrp And Put Them On A Crewcab Short Bed. The Extra Pipe In The Kit For Use With The Long Beds Is A Perfect Fit For Deleting The Muffler. Now You Got A Straight Piped Truck!!!!

go to any truck repair shop they carry 3.5" pipe and elbows. I when to Western star you can email me i will send you a picture dluther@shaw.ca

Has anyone upgraded to a 4" exhaust (including the muffler) and replaced the kitty with a test pipe? What's That sound like?

Ed

This has been done by several people, you should do a search.

http://www.bmdmax.com/downloads/LB7Exhaust.wav

Takes a min to load but that is what it would sound like if you had your ear right next to it

I have 4" exhaust with no cat and a resonator. It sounds fine by itself but it is a bit loud when I am pulling the rv down the road a 70 mph. I am going to maybe put a muffler on to quiet down the drone.