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after my 2nd set of dynatech cats failed i just finally took them out.... i then added two 18" resonators becuase i knew it would get louder. well i didnt anticipate this, its just rediculous. the low rumble and drone gives me a headache.

 

what are you all using? and how EXACTLY does it sound?

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Leave the cats out! They are nothing but trouble in the long run. The drone is nuts in my truck. So bad that I have to where ear plugs sometimes when I am warming it up in the pits. I would suggest to get big mufflers (they can still flow the same just bigger) and be sure to run the exhaust all the way to the rear of the car.

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after my 2nd set of dynatech cats failed i just finally took them out.... i then added two 18" resonators becuase i knew it would get louder. well i didnt anticipate this, its just rediculous. the low rumble and drone gives me a headache.

 

what are you all using? and how EXACTLY does it sound?

 

 

Lose the resonators, get a chambered muffler (or two :lol:), and have it exit behind the truck (at least behind rear axle). Make sure the mufflers (or even the resonators now) are offset, as in not mounted perfectly side-by-side. That will help with a lot of the drone...

 

My camaro doesn't have cats, and its exhaust used to be dumped... The noise was unbearable... I took off the turn-downs, put in some 90* bends and put the tips out behind the back bumper and it was about about a 70% reduction to in cab noise... Food for thought.

 

 

 

BTW... where are the sound clips?

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If you are running a low AFR blown application, eventually your cats will run into issues IMO...even the high dollar metal substrate ones such as Random Technology. My suggestion is to look at the huge magnaflows (something like a 24" case) that should mellow it out a bit.

 

My metal substrates showing some signs of failure:

 

IMG_1196.jpg

 

My new improved design:

 

IMG_1349.jpg

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You can also try to use dynamat in the cab or they do have some stuff at Autozone that say it helps with the sound and its a spray. You could spray that under the cab. Just some ideas. However, I have OBX LT's with no cats, y pipe, 3'' flowmaster super 44 exhaust that runs back to the stock location. Everyone says it crazy loud, but I don't have any problems with drone.

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ok i shoulda added more info....

 

i first had dynatechs, corsa touring. it sounded just weird IMO. so i took it off, kept the cats, added a 24" dual in/out magnaflow, and dumped it before axle. the drone was bad. so i had the exhuast exit out the rear corners, like youve all seen. that helped ALOT. however, with the addition of the rollpan, i could see the entire pipe and it pissed me off. then my cats failed, again. so i took em out, kept the 24" magnaflow, added two 18" resonators and moved the exhaust to right in front of the rear wheel like art and chases setup

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...My new improved design:

 

IMG_1349.jpg

:lol: Yup my first mod:

 

stealthcat.jpg

 

Cats suck. I have he Corsa Touring w/o cats and it sounded just amazing when I had factory manifolds; when I put the AEM headers on it got a lot raspier, doesn't sound as good. I'm going to change headers to larger ones (Stainless Works). Stainless Works headers + gutted cats + Corsa catback on a TBSS is just flat-out sex.

 

The key I have noticed to eliminating the drone is to get the catback piping right, it's not the fault of the mufflers but rather the wrong diameter or length of tailpipe (it's a resonance thing). Switching to a quieter muffler (like the long Magnaflow) won't eliminate the buzzing, it will just make it quieter maybe even quiet enough that you won't mind the buzzing but it will still be there. Unfortunately I don't have any educated suggestions :( but there are several guys that have used dual Flowmasters and Hooker Aerochambers and not had any droning so the secret's got to be the pipe lengths.

 

Mr. P.

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steve you nailed it.... its the headers are what kill the corsa sound, and raspy is a PERFECT word. i believe my resonance is due to the piping placement mainly, but i know so many people did it, that they all cant possibly be living with this noise....

Edited by kelleyperformance (see edit history)
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To get the pipe length thing worked out, you can use lengths of exhaust tubing laying on jack stands and slip the mufflers on and let the truck idle. There's enough slop in most collectors that you can do this without much problem. Experiment with putting different lengths of pipes on before you weld anything in place. Muffler placement is critical to killing drone, just as much as total tubing length. I've used this method several times and never had a drone issue on any of my custom exhaust systems... er.. well, except the 70 vette with the unmuffled side pipes, but that was intended that way. :lol:

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