Stock exhaust paired with kooks headers and hi Flo cats
 

Does anyone have headers and hi Flo cats with the stock exhaust?
If so, how does it sound?
Will this work?
Will it affect my HP numbers?
Will I have to re-tune?
I have the above, but with a Corsa cat back, and it has grown a bit too loud for my taste. So I was gonna bring my stock exhaust to the muffler shop tomorrow for a replacement.
My other thought would be to install a set of resonators, but if there is no performance difference, and I have the stock exhaust already, I could save some much needed dough$.
Any thoughts??
Rob

Anyone? Help :-(

You have a manual so you don't have the big resonator the autos have. My stock mufflers with a magna flow x were louder than my magna flow catback we pieced together at WOT

I have ARH LT's, HF cats, stock cat back system except for the GMPP "touring" axle back mufflers. Rich deep sound in normal driving, in fact not too much louder in the cabin than when the car was stock. Highway cruise at 60 to 90 mph is comfortable, no drone and comes no where near over powering the radio. Both my wife and I are in our 50's and she drives a Caddy DTS and she does not find the sound level in the cabin of my car a problem......until I put my foot in it and then it gets loud. I think the factory LS3 cat back system is pretty good power and sound wise, especially in cars with under 450 rwhp. I doubt it would affect your tune or power levels.
Ed M.

I asked that same question before, and several told me that the stock catback is very free flowing and that it sounds great with a set of headers and high flow cats on the LS3.

1. Yes - Kooks LTH w/HFCs
2. Sounds great!
3. It will work
4. No - stock exhaust flows very well
5. No reason to retune (see #4)

Try it - you will like it.....stock sound at idle, nice roar during hard acceleration!

Everytime I have attempted to put headers and hi flow cats to a stock exhaust it has resulted in the internal baffles of the mufflers being destroyed over time and needing replacement anyways. There are several people on this site that have had this exact issue. Do yourself a favor and replace the cat back if you are replacing headers and cats!

Ahhhh! This is so confusing,
When I installed the headers, hi-Flo cats, and Corsa cat back about a year ago, it sounded awesome, but has gotten increasingly louder over time, so it is now way too loud.
I leave early for work and have to push my car out of the driveway and start it on a rolling start, so I can get out of here ASAP. I even have had a neighbor or two comment on the volume, so I think I blew something out internally with the exhaust and the hard roadtrack days I do a few times a year.
:-(

I have kooks with HF Cats connected to stock exhaust. Sounded great until (blownSS got it right) the baffles got blown out. Now I get this high pitch pingy sound in a certain RPM range, and it is embarrasing to hear. I've taken mine down the track about 25 times though so that might have something to do with me blowing out the stock, maybe in normal wear and tear it would hold up.

I have a hard time understanding why it would get louder over time. The corsa mufflers have no glass packs or baffling that could be destroyed. One thing I would check if I were you is the high flow cats. I've heard the kooks hfc's are low quality. Maybe pull these and see if the internals are damaged/destroyed.

Also, I don't know which corsa version you have, but the L99 version comes with a resonated x-pipe. You might could call corsa and buy just the L99 x-pipe if you don't already have it.

YES YES YES +1..... battling the stock axleback rattle right now...... The stock cans lasted a whole 800 miles before shaking themselves apart. Thay just cant handle the added flow to the LT's with Hi flows cats(or no cats). Be warned...... swap out the mufflers too..... better yet, do the whole system front to back. I wish I did:facepalm:

It probably is my cats!
I used to love the way my car sounded, and I love the Corsa raspy tone, maybe I will check them out. How do you know if they are bad?
If they are, I will replace the hi-flo cats and see what happens.
What is a Good brand of hi-flo cat that wont add too much volume??

I'd just remove them and make a visual inspection. If the packing material looks busted or melted (pics mid way down this thread http://www.camaro5.com/forums/showthread.php?t=183230) it could be your problem. Sorry, I do not know a reputable high flow cat.

Has anyone tried Solo Resonators?
That may be the way to go!
They claim a decrease in volume of about 20%
I saw that picture of the destroyed CAT, that is brutal!

OK, if I pull out the cats, install some straight pipe, and the resonators, will I need to re-tune? Are straight pipes louder than hi-flo cats?
Help!