[oldman]

So even though I have not tried the LT with no cats yet, by the sound change on my current setup: stock headers, CA cat deletes, stock secondary cats and the Borla 60608, I feel that it should work with LT and no front cats, still keep the secondary cats. My thinking is think two dampers before the suitcase and all is well:
stock it is cat and cat
Me: 2nd cat and Borla 60608

[Bosse'sBoss]

Could I run this setup on my Camaro SS MT with the stock NPP exhaust, just by removing the secondary cats, and installing resonators. I want a stronger exhaust sound, but not the crackle and pops, and no droning if possible.

[6spdhyperblue]

Originally Posted by Bosse'sBoss

Could I run this setup on my Camaro SS MT with the stock NPP exhaust, just by removing the secondary cats, and installing resonators. I want a stronger exhaust sound, but not the crackle and pops, and no droning if possible.

The crackles and pops are in the tune. You need a tune to remove that

[gmcvt]

Oldman, I wonder if I have the resonance that you are talking about. I ended up with a great deal on New Era full cat delete and not long after installing them, I installed a magnaflow muffler in place of the factory x pipe. This in concert with the factory NPP muffler. What I have noticed is pretty darn specific, right around 1500 rpm there is a resonance that would remind you of maybe a driveline/driveshaft vibration. Goes away by 1800 rpm. MPH makes no difference, throttle position and rpm do, so I can only deduce that it is some sort of very low frequency resonance in the exhaust. It didn't start until I had the magnaflow unit installed. Didn't do it when it was just the cat delete through the factory x and factory muffler.

[6spdhyperblue]

I’m gonna be selling a lightly used 60608 in a minute

[gmcvt]

Probably should have gone that route but I didn't.

[gmcvt]

Originally Posted by 6spdhyperblue

I’m gonna be selling a lightly used 60608 in a minute

Why are you selling?

[6spdhyperblue]

Its not on the car at the moment so I had a lift I would just put it on. I do the work on the car myself and just not up for it this winter..also decided not to touch anything and try for a 10s slip again in the spring.

[SomeGeoffGuy]

Originally Posted by gmcvt

Oldman, I wonder if I have the resonance that you are talking about. I ended up with a great deal on New Era full cat delete and not long after installing them, I installed a magnaflow muffler in place of the factory x pipe. This in concert with the factory NPP muffler. What I have noticed is pretty darn specific, right around 1500 rpm there is a resonance that would remind you of maybe a driveline/driveshaft vibration. Goes away by 1800 rpm. MPH makes no difference, throttle position and rpm do, so I can only deduce that it is some sort of very low frequency resonance in the exhaust. It didn't start until I had the magnaflow unit installed. Didn't do it when it was just the cat delete through the factory x and factory muffler.

Magnaflows make a great exhaust, but they are prone to the resonance that you describe. Every muffler from them that I have ever seen is fully fiberglass packed with a perforated pipe that runs pretty much straight through. The good side is that they flow well and sound good, but there is zero noise cancelling relative to drone.

-Geoff

[Clearly_Canadian]

Originally Posted by 6spdhyperblue

I’m gonna be selling a lightly used 60608 in a minute

I would be interested. I love my exhaust notes. But the start up bark is a little too extra for me.

[gmcvt]

Originally Posted by SomeGeoffGuy

Magnaflows make a great exhaust, but they are prone to the resonance that you describe. Every muffler from them that I have ever seen is fully fiberglass packed with a perforated pipe that runs pretty much straight through. The good side is that they flow well and sound good, but there is zero noise cancelling relative to drone.

-Geoff

Thanks for the input. I had a similar stock muffler/magnaflow combo on my 5.0 and it worked a bit better there but what your saying sounds absolutely spot on. Some of it may be aggravated by the use of the stock NPP. It also has kind of an annoying muddled sound between 1900-2300 rpm that in my opinion sounds pretty crappy. Once you get past that, it sounds pretty good. At some point I will have to do something different.

I also dont know what difference it makes between full cat deletes vs LT's on the sound. If any.