I have just recently installed the vibrant header-back exhaust system and it is way to loud. I do have the high flow cats. What would be the best sounding and cheapest way to quiet it down a little. Help is appreciated. Thanks!!

 

the vibrant is known to be very loud, and sound like a chainsaw. ways to quiet it down are to put extra resonators, or if you can't fit one a better resonator than what you have now. that's about it.

 

should of kept the stock exhaust on and got a axle back

 

is it all welded together or clamps?

 

Is it just loud or is it really bad sounding like somethings not right? All of your bolts are tight, right? If you have even one bolt loose where the header/dp meet (or anywhere else on the exhaust) then it can sound loud as hell and like crap.

 

doesn't change the stock resonator, which won't flow as much as a performance.

the vibrant is clamps. the downpipe bolts to the header just like the stocker, the downpipe bolts to the catback just like the stocker, and then there's a band clamp that holds the catback together right before the torsion beam.

 

+1 invisi-rep for being helpful

 

yours may sound better because you have the gmpp exhaust which will help quiet things down. a full vibrant exhaust typically doesn't sound to great, even whan all is installed properly.

 

I think the top bolt where the header and downpipe meet might be a little loose. I can hear it leaking at idle but its not too bad. I have to make my way to the muffler shop b/c there is no way i can get any kind of tool there to tighten it. There is not enough room. I still dont think that will make it sound a little quiter and better though. Oh i really appreciate all the help. I dont know of any other forumns that are as helpful as this one.

 

Yea that top one can be a bitch sometimes. Wouldn't happen to have a sound clip or video of your exhaust, would you? That'd make it a ton easier to figure out if it's just the exhaust or whats up.

I wasn't comparing it to mine, but that's 100% true. I was just asking from experience with some other guys who thought everything was tight but they had a big leak somewhere which made it sounds like hell.

 

i used a small crescent wrench, and alot of aggravation about 1/15th of a quarter turn for about an hour to tighten those on people's cars

 

Also for the mods you have... your set-up should be zzp dp/header combo 3inch with 2.50 exit for dp so it can go onto your stockie and an axle back. you would have a full 2.50 set up after that besides the dp being a 3 inch... were you a impulse buyer with the exhaust you bought? i completley understand i'm a impulse buyer with DC and DVS shoes. i love em

if i see a pair i'm like YES mine

 

Give it up for NJ balts to the rescue haha or moreover the tri staters and MD.

Anyways try to get those bolts tightened and go over your whole system for leaks.

Do you hear any rattling or is it just loudness?

 

I got to the top bolt of my stock downpipe pretty easy.

 

I put a resonator on my exhaust because it was too loud, it sounds great now. I would try that.

 

Get a dynotune muffler.

I had one on my old cobalt and it was quiet as hell.

 

I dont have any clips at the moment. When it it cold i kinda hear a little rattle. I will try using a small crescent wrench right now. I am going outside and give it a try. Its nice when you can work on your car at work. I am a career firefighter. I keep my car in the truck bay. I will brb.

Dang...we dont have a small enough crescent wrench

Bump...Any other ideas

 

^^firefighters ftw!!!!! You have my dream (and future) job my friend.

 

take out that GM resonator if you have the GM Sport package and put in 2 reversed glasspacks to baffle it.

Mine was too loud as well, and sounded like a honda after 3000 rpm.

Oh and be prepared to keep tightening the bolts over a week or so. The manifold gasket has to seat right.

 

The whole setup is vibrant

 

start welding in resonators

 

what kind would be best

 

zzp whisper i heard is good. i use glasspacks as do others. I dunno, search ftw?

 

Bump....Ideas?

 

The stock cat-back is 2.5" until after the first 90deg bend. After that it goes 2.25 to make all the complicated bends around the torsion beam. So making an axle back that gets rid of the 2.25" portion requires building alot from 2.5" bends.

When I got my car the previous owner put a straightthrough (2.25") muffler on the stock catback, which I thought was pretty loud. It was poorly welded on so it began to rattle. I replaced it with a true 2.25" reverse flow (typicaly referred to as a "turbo" muffler in the aftermarket industry) and a resonated tip. It is still louder than other stockers that I've heard and sounds it's best in the lower rpm range. can't imagine what it is like with a header and all 3".

It realy comes down to what you mean by loud. If high pitch rasp is the problem, better/more resonator would help reduce it. If it's total volume that's too much, then you face replacing that straight through muffler with a more restrictive one like a reverse flow (but still 3" internal) or chambered design. Which might not be all that bad since folks seem to think 3" is to big for most cobalt setups anyway