Daniel60

Roberts Automotive in North Charleston, the mustang shop that I frequent informed me that our engine is actually better with stock cats. He said the engine wants back pressure and that free flowing exhaust will rob you of lower end torque but you will gain it in the 5,000 rpm range. Like $hit who drives at 5000 rpms? I thought I lost a little when I got the Mac Axle backs and maybe I didn't but now I do know I will forget about a pro chamber or cat-less x -or h-pipe. He said you could get the pro chamber with cats but it would be pricier however the sound isn't going to be as noticeable unless the cats go. Everyone who already knows this than cool however if you didn't know I thought youshould. I hear people complaining all the time about those X-Pypes with no cats, on how they leak and so forth. Maybe leaving alone is better. I do like my Macs and I wanted more sound but now I'm thanking maybe I should have went with amuffler that includes more back pressure if there is such an animal and sounds good? Also I was informed before unless you have forced induction you aren't going to see much difference with Long tube headers either. As everyone knows now the shortys aren't even observed as actual horsepower gains for the S-197s.

Wally39

I just don't see how back pressure is a good thing. Back pressure = more work load on the engine.

Daniel60

Well to be honest this isn't the first time I have heard that we do better with cats.

SonicBlue05GT

i think these cars without cats sound like old tractors trying to mate with crop dusters

the LS1 has very, very close sound to it.

shame they can't sound like the 99-04s [&:]

Daniel60

Christ that's the sound I want is the 2-valve. I drove the 2-valve with flow masters and man it's pure rock n' roll but interesting enough it wasn't as quick as the 3-valve. These are considering both cars are stock.

PiggySmallz

my borlas sound great with a prochamber no rasp weed whacker, just deep loud roar...i'll take that along with my acceleration over a 2V. 2V's sound like pure sex but my 3V doesn't sound bad at all.

rshamekh

I'm happy with the gains I got from my O/R midpipe. It sounds good too.

Hey piggysmallz, have you heard the stingers with Pypes O/R H in person? if so, how does it compare to your setup with the prochamber? is it worth the upgrade?

Daniel60

PiggySmallz do you have any opinion on your performance? Do you have the pro chamber with cats or without? I like to hear your answer sir.

PiggySmallz

rshamekh: yes i've heard them with an O/R H. I helped a buddy install it on his car with stingers. IMO they both sound great. Mine is a little deeper but his is slightly louder. You can't go wrong either way. I also get no trumpeting, but I have an auto tranny so I'm not sure if that changes anything. I have to be honest and say there is a small leak in this thing that I can't get rid of. It's barely noticeable and was a lot worse, but once I hear something like this it drives me crazy haha.

Daniel60: I didn't really feel a difference in performance. I installed the prochamber a week before intake and tune. It felt the same, if I did lose anything it was minimal. My prochamber has no cats

rshamekh

Nice! Didn't know the prochamber gets rid of the trumpeting, I might think of upgrading to it.
I have an auto tranny too btw. I don't think it has to do with trumpeting though, because my setup trumpets at high rpms.