I recently had my exhaust done i had the cat and the resnator cut out and 2 flowmaster super 44s put on with 2.5" to 4" tips now when i start driving there is a noise coming from the back that sounds like a metal to metal type of noise when i start to accelerate, at idel it sounds good i dont know what the noise is if someone knows please let me know so i can get it fixed its a 2002 monte carlo ss with a 3.8l engine

 

Thats the crap sound of our engines. We call it raspy.. The most you can do, and your best bet would be get some kind of resonator/glasspack and put it where the cat would have been..

Ive had thrush "welded" mufflers, those are made the same way and yea they sound really bad. They have sorta "walls" inside to manipulate sound instead of the more common chamber/fiberglass/stock style built mufflers.. My point is, is that these are not the right kind of muffler for our cars, as you have found out.

Do you by chance have access to any fabrication tools? I could give you some pretty good advice if youre able to do some exhaust work yourself..

 

I would get under the car and start shaking up the exhaust too. I wonder if it's loose, or a hanger is poor.

 

The cars just sound like that unfortunately. When I had my car running no resonator and Borla XS Pros it was very very raspy. Currently I am running nothing but a 18" glasspack in where the resonator used to be, and it sounds pretty good, but at high rpms, specifically when you let off the throttle at high rpms, it still rasps. To me it sounds like the stock y-pipe is being restrictive, so my next step is putting a bigger aftermarket one in as well as finishing making the rest of the exhaust 2.5". If you have money sitting around and want to try a bigger y-pipe by all means, let me know how it goes. :P

 

I have played with these 3800 exhausts for quite some time now.. I can pretty much tell you anything you need to know regarding what "this" does or how "that" makes it sound.. Im talking different materials, sizes, angles, difference in bending methods, different placements of components etc..

Bigger Y pipe amplified the rasp unbelievably so.. This was 3" into 2.5" y pipe.. It wasnt what I was expecting for sure.. It seems like the larger pipes give more of this rasp. I know this is contradictory to everything youll read about exhaust tone but its true with our 3800s..

I am actually ATM in the process of swapping the piping from the rear of the glasspack into the T pipe to a smaller size. Im going try the stock 2.25 and hope it doesnt create any restriction.. I would think not because its only a couple feet..

My current setup is 1.5" primary headers into 3" DP into 2.5" 36" glasspack back into 3" going to the rear wheels where it then splits with a T pipe (instead of Y pipe). From the T pipe I have crush bent 90 degree pipes into thrush welded mufflers. It would sound a bit better if I could get the flowmaster delta flow 40s and although they are built inside almost identically, the flowmasters give a much deeper tone(exhaust shop let me slip them on to try them). I also plan on putting on resonated tips in the next week or so..

This setup almost eliminates that crappy sound and gives it a very unique one, its actually really cool sounding.. You hear it and you know youre not trying to imitate a v8, its not obnoxiously loud, not loud at all really, and best of all its a consistent sound throughout the RPM range..

One thing I will say tho... The headers seriously intensify that awful rasp.. So if you have stock manifolds, youre kinda in luck..

Hey any questions, Id be more than happy to help.. Been playing this stupid exhaust game for YEARS now..

 

I need to correct myself from the first post i made in this topic so I dont sound like a damn fool..

ALONE the "walled" type mufflers (thrush welded,flowmaster 40/44) are a bad idea..

 

Thats interesting that a bigger y-pipe would increase the raspiness. When I listen to my car it sounds like there is a restriction, and the only thing left stock on my exhaust is about 2 feet before and after the y.

I'm curious to know where the rasp originates, is it from the engine itself? Is it quiet from the engine but then is amplified by something? I would be curious to hear from someone who ran a 3800 without any exhaust manifold and see if there still is the rasp

 

From what ive read on the forums here its caused by the screwy firing order of the engine..


OH MAN I couldnt imagine what that would sound like without any manifold..

I had a ford tempo way back when that had a hole in the manifold.. It would set off car alarms driving thru a parking lot....

Lol, id like to hear it tho if anyone want to be a guinea pig..