I have heard that the exhaust that comes on the WS6 is where most of the extra horsepower comes from and that the Ram Air is mostly just an appearance mod. If I was to buy a "cat back" would there be any gain or is the factory exhaust good enough?

 

You'll get a little out of changing the muffler for a good free flowing piece. The pipes are mandrel bent stainless... if it ain't broke don't fix it.
The cats are the other restrictive part of your exhaust besides the muffler, so an ORP helps and headers are the final touch to a really free flowing exhaust.
Getting a little off the subject. The answer is: Get a good muffler.
Dave

 

Dave I have a Flowmaster 2 chamber on it now. I was wondering about the Rest of the exhaust. You answered my question though. Oh by the way, I don't mean to sound ignorant, but what is ORP?

 

ORP = Off Road Pipe.

 

Off road pipe is what is used to delete the cataylic converters from a car. The name comes from the manufacturer's note that the pipe is for "off road" use only.
Dave

 

what do you do with the O2 sensors when you get rid of the cats and doesn't the service engine light come on without the cats?

 

You need some O2 sims, try thunderracing.com. That will fix that problem. And get some long tube headers. Becase if you decide to get a cam and head it will pay off big time. don't do like I did and start out with the shorties.
check out this dual setup.
http://www.geocities.com/kmook123/exhaust2

 

Flowmaster=Loss of power...

Stock exhuast can flow as well if not better then some aftermarket mufflers.

 

Umm, maybe aftermarket K-Mart mufflers. Any of the namebrands will outflow the stock setup by far.
Borla
Dynomax
Corsa
B&B
ATR
...The list goes on and on...........................................

 

Did you miss the word some? Cause I think you did...

 

A few months back, GMHTP did an article on this exact thing. They took a WS6 to the dyno and got the baseline, then they tried different exhausts. Care to guess? MINIMAL (if any) gains.

Personally, I bought my WS6 used and the owner had put a Flowmaster 80 muffler on there. I LOVE the sound, but I know that it's restrictive. So, I'm adding the electric cutout this winter. That way I can enjoy my Flowmaster sound, but open the pipe when I need the extra HP that the Flowmaster is stealing.


I'll see if I can find my copy of the article, but if someone else has it handy, maybe they will post the highlights in here.

 

Stock car + aftermarket exhaust = minimal gain
Modified car + aftermarket exhaust = Nice gain

Cobrakiller: Most people think of the same brands when the work aftermarket exhaust comes out. Your statement was true but most people won't think of a Kmart muffler when a topic about aftermarket mufflers for LS1's is brought up.

 

Stock Y-pipe has an oval shaped pipe on the driver's side. Pretty cheap if you ask me. That's why I went Hooker Longtubes with a 3" off-road pipe to a loudmouth.

Tone @ idle = awesome
Tone between 2,000 & 3,000 = Worst sound you've ever heard
Tone @ WOT = decent

 

Imagine:

Take a cross section of the flattened Y-pipe. Calculate it's area. Now calculate the area of the other Y-pipes. If the area is the same then neither is better or worse. It could be in the shape of a star, a square, a triangle, a circle and yes even a flattened oval. But as long as the area (and therefore volume) are the same, there will be no difference in performance.

It is flattened for additional clearance. Have you ever seen under a Winston Cup car? Guess what. The pipes are flat and wide.

Thank you physics professor.

 

When this topic is brought up, which is rather constant, people keep on quoting the one test performed by gmhtp and state the outcome was negligible on a ws6 or ss car. I do not personally support one test as being concrete evidence that a catback will not add a significant performance gain over the ws6 exhaust. How do others feel on this ?
I put a catback on my 02 ws6 and was impressed with the sotp gains I made but unfortunately in my end of the country there are no dynos to support the gains.