I have a C7 LT1 with a S/C and Meth kit. 11 lbs of boost and 686 WHP.My question is if I cut out the cats before the blower destroys them how much louder will the car get ? Keep in mind I do not have a NPP exhaust because I want to keep it very quiet. I am extremely happy with the way it sounds now and what can I expect with hollowed out cats.

 

I'm guessing the car is already tuned so installing test tubes as they are refereed to won't cause an issue. The secondary cats in the factory x pipe act more as resonators and really do a good job of taking the rough edges off the exhaust sound before it reaches the axle back mufflers. just my .02

 

In the c7 will not chg the sound much at all. May not be able to tell any diff's to the system. You may just want to pull them then pull all the guts out of both front & rears & keep both under the car. Robert

 

Thats the plan.

 

jdarc1, your car already has a tune correct ?

 

I have A&A V3 Si @ 8 psi and TSP long tube catless. I also have NPP and with the flaps closed it is nice and quiet. Zero drone at hwy cruise. However, there is no way to keep the flaps closed at WOT. That's when all hell breaks loose. It sounds like Bob Glidden's pro stocker.

I would expect a change in sound for sure but will assume it would be very tolerable with no cats on a stock non-NPP muffler.

Side note. I had a S/C 1995 Z28 Camaro with a high flow Edelbrock muffler and swapped a straight pipe in for the cats and hated it. It stayed on for a one hour test drive and was removed. It sounded like a pickup truck with glass packs. However, this would relate little to the C7. Just an example of how changes can make a big difference!

 

imxz28, sure as hell you'd be one pizzed off puppy if after all the work you've done, it didn't sound like Glidden's car at wot ! I'd hire a high dollar witch doctor to hex my tuner ............

 

Yes.

 

I'd have someone make a set of "test tubes" to replace the up oe stream catted pipe assys and try running with the catted x-pipe for a while to see what the sound is like. You can always have those removed at a later date if things are still to quiet for your taste.

 

The system on these c7 is not like the c6 & c5 system. On them the headers cat delete would make the car sound much louder. But the c7 even without the NPP on it, it still has the one piece what ever before the cat back that doesn't make it as loud.

Plus these new cats are also made with diff guts than the c5 & c6 cars that will made them last longer. But still with the boost I would say will burn out in time.

 

Its because of the boost is why Im removing them. I would not want the material to blow into the mufflers and then I have to replace them as well. My exhaust is completely stock and no headers or axle backs. Nice sleeper with big HP, I want to keep it that way. I was just wondering how much louder it would get ( I am assuming not much ) without the cats.

 

I understand what you were asking in your question. The stuff from the cats it will just like burn it out & make them not work no more. That with the mufflers being what they are it would take years & years if it did at all to damage the mufflers.

 

If the front cats burn up--all that melted material will lodge into the rear cats and eventually plug them up creating a whole other issue

 

Do you have verifiable proof of this ?

 

^^ This. To be honest, it isn't a good idea to be running meth with the cats still on the car.. recipe for disaster..

 

Ive seen cats on a blown/meth Camaro burn up 1st hand.

 

My mods are ECS 1500, AR LT, Alky control (100% meth) and a tune. My car currently puts down 659/650 and its an A6 2014. I have the stock exhaust (non NPP) without cats and I was also concerned to about the sound, but running 100% meth I rather deal with the sound then the sound of a failed motor. I wanted my car to be a true "sleeper" so to speak and was worried about the smell and the noise. All my fears were put to rest when I first started it. I LOVE the sound of it, as it is only a bit more rumble then with the cats (very subtle). I get none to extremely minimal exhaust smell (sitting in traffic with the windows and top off you will get a little smell but its only noticeable if your looking for it). BUT when you get into the gas at WOT it sounds INCREDIBLE! I get so many compliments on the sound of the car and people are wide eyed when they hear it from idle to a WOT run. I've had a few highway sprints and everyone is shocked at first how quick the car is and then how it sounds. (a big plus is that if you are using the paddle shifters you can hear the boost whoosh and sound from the exhaust at each shift). I "almost" went and purchased the Borla exhaust as I always put an aftermarket exhaust on my vehicles, and i can truly say that I am glad I didn't this time. Trust me you wont be disappointed.

 

I'd love to see your video, but when I click on it, it says "video is private"

 

try it now

 

Sad ......... Too bad it wasn't a Mustang .............