Exhaust Options

[drdave81]

I'm planning and starting to get parts together for a spring top end build on my 01 Denali. I've decided to go with 5.3 long tubes and then replace the existing magnaflow catback with a 5.3 cat back. The whole exhaust system can be replaced much cheaper than just buying 6.0 specific long tubes/down pipes. I know going to long tubes, the sound is going to get louder. Currently, for this being the daily driver/family trip vehicle, I don't want the exhaust to get much louder, so what do you think would be a good way to go to keep the sound down? Is there a quieter catback anyone would recommend while adding long tubes? I think I saw something about adding a resonator as well to quiet it down a bit?

 

[Cobra]

Flowmaster 17419 Flowmaster American Thunder Cat-back Exhaust System

For the person who is looking for an aluminized steel cat-back exhaust system with an aggressive exterior tone and moderate interior tone. The American Thunder® system is heavy 16-gauge mandrel-bent aluminized steel tubing for durability and maximum performance. Includes a Super 50™ Series...

www.holley.com

been running this setup for years along with y-pipe and pacesetter ceramic coated long tube headers. Never had issue with it being to loud till now. recently installed a stage V RPM transmission and circle D convertor 2600-2800 stall. The truck is much louder since doing so but I think it's just time to replace the muffler. Possibly broke a baffle inside and hear a loud vibration.

 

[iamdub]

I'm planning and starting to get parts together for a spring top end build on my 01 Denali. I've decided to go with 5.3 long tubes and then replace the existing magnaflow catback with a 5.3 cat back. The whole exhaust system can be replaced much cheaper than just buying 6.0 specific long tubes/down pipes. I know going to long tubes, the sound is going to get louder. Currently, for this being the daily driver/family trip vehicle, I don't want the exhaust to get much louder, so what do you think would be a good way to go to keep the sound down? Is there a quieter catback anyone would recommend while adding long tubes? I think I saw something about adding a resonator as well to quiet it down a bit?

IMO, long tubes, alone, aren't gonna make it much louder. If your headers still have cats, then that'll be the saving grace. No cats=LOUD.
You said you're getting a 5.3 cat-back system, so I assume you mean a factory 5.3 muffler system and you'll have cats (since it's "cat-back").

If no cats, then you're gonna need a lot of muffler. Resonator is more for "clean up" than muffling.

 

[Bigkevschopshop]

cats keep things mild, borla xr1 I have put on two rides now, sounds great, deep and mellow.. Something to keep in mind I guess, drone... My 03 tahoe had some when under heavy load but it did sound great while doing it...

 

[drdave81]

IMO, long tubes, alone, aren't gonna make it much louder. If your headers still have cats, then that'll be the saving grace. No cats=LOUD.
You said you're getting a 5.3 cat-back system, so I assume you mean a factory 5.3 muffler system and you'll have cats (since it's "cat-back").

If no cats, then you're gonna need a lot of muffler. Resonator is more for "clean up" than muffling.

Most cat back systems don't have a converter with them. They start behind the cat. At least any of the ones I've looked up for our vehicles, or any other vehicle.

I wasn't sure if anyone was running an ORY with a different exhaust system to keep things quiet. I'll probably have to just keep some sort of converter on there to keep the noise down. Even still, any 5.3 system is going to be cheaper than the 6.0L from Kooks or ARH.

 

[iamdub]

Most cat back systems don't have a converter with them. They start behind the cat. At least any of the ones I've looked up for our vehicles, or any other vehicle.

I wasn't sure if anyone was running an ORY with a different exhaust system to keep things quiet. I'll probably have to just keep some sort of converter on there to keep the noise down. Even still, any 5.3 system is going to be cheaper than the 6.0L from Kooks or ARH.

Right, that's why I specified "cat-back".

I have headers and a catless Y-pipe. With cats and stock manifolds, it was perfectly fine with an 18" muffler. That same exhaust, but with no cats, was obnoxious. I added a 22" muffler to that 18" for a total of 40" of muffler and it's still probably what some might consider a hair too much for a family cruiser.

IMO, GM put the larger exhaust on the 6.0 because it was needed. Putting the smaller diameter tubing of the 5.3 would result in a loss of power and possibly efficiency (less fuel economy). Although, it'd likely just be realized at higher RPM so you wouldn't have as much passing power on the highway. You might have more off-the-line power, though. If you drive like grandma and in the city all the time, you'd be ok.

Also, no cats stink, and it's a stick that sticks to you- in your clothes, your kid's clothes, etc. You can't cruise and especially can't idle in traffic with the windows down.