Two weeks ago my 12v was just as quiet as a mouse in the cab. Still had a good rumble outside, but not terribly loud. It had an HX-35 with 3" downpipe and right at the downpipe it was connected to a 4" exhaust with a reducer, a small piece of flex and a couple band clamps. ONLY thing I changed was I put my Silver Bullet turbo on it, and put the 4" downpipe on. Still has the small piece of flex and two band clamps. Now it is obnoxious to ride in. It is too loud in the cab, with not much increase in exhaust noise outside the cab. Could it be that bc the new downpipe and old exhaust did not line up perfect that it is resonating real bad where the connection is not pefectly lined up? I use to have a Single 5" straight stack on my 24v and it was no where near this bad. I had a 5" exhaust in mind for the 12v, but if it is any worse than it is I wont be able to sit in the truck cruising around town.

 

Anybody got any suggestions as to what I can do to take care of this?

 

Dont know what to tell you other than getting a new exhaust with a muffler

 

Check very carefully down pipe is not touching the cab. It will vibrate and resonate horribly.
I had one truck with almost same issue only it was barely touching the frame crossmember.... Holy schmokes that was noisy !!!

 

I second the vibration possibility. I had my copper boost line rub on the cowl the other day and it sounded gawd aweful. I would have never guessed what it was before i started to check it out.

 

like was already said, check for things touching or check for loose connections

 

Sounds good guys, preciate the responses, I will disect it later in the week and give an update. Travis

 

Just an update, crawled up under the truck when I got home this past weekend, and couldn't see anything. As in, I mean really bad exhaust leak and whole underside of the truck was black, but I didnt see anywhere where the exhaust might be touching anything, so Im assuming its the leak. The tranny is out of the truck right now, but I plan on fixing the exhaust when I throw the tranny back in. Thanks for the help.

 

Exhaust leak would definitely do it! I ran my 24v for a month with just a downpipe, and the noise in the cab was so bad, it made my ears pop like being on a plane, and would give me one of those "deep" headaches if I spent much time in it. 4 inch exhaust is on now, and what a beautiful thing it is.

 

If you can get rid of the flex pipe I have found it tinds to be louder than regual pipe. Had a friend made a 4" out of flex pipe ( just temp to get it on the road) from the DP to the stack and was twice as loud as when I made him a pipe setup. It was on a power stroke so it was realy bad.

 

Got everything straightened out finally. Just used a small piece of flex and had to cut the exhaust hanger near the tranny off and reweld it. Back like it used to be now. Just a tad louder than before, but not annoying. Thanks for the help guys.