Where can I get an after market exhaust for an 01 SSEI? I have found a few sites for the 3800 but none have specific exhaust for the the Bonnevilles. Same thing with the PC. I am about to start modding it semi lightly and you can't do that with out PC and exhaust work. Thanks guys.

FALSE....on the exhaust part that is.....some of the quickest cars run/ran a totally stock exhaust. The stock system is good, it has Bosals from the factory...only change the mufflers for sound only, there is no performance gain by changing them, you cant outflow the stockers

and PC....do you mean the PCM??...the PCM changes can be found at Intense-racing.com

Are you sure about that, I can't see GM putting out something that great preformance wise for a four door sedan. I have a 2001 SSEI just to be a little more specific. I just can't see that being completely accurate, the mufflers might flow well but I can't see the whole cat back system flowing as well as a good after market system. What about the exhaust manifolds, I know they can't out flow a set of good headers. Any one know who makes the better set for these cars? The Other Guys seem like the way to go so far. And yes I need my muffler a little louder then stock. I can't hear the car run, which is going to cost me more in tickets in the long run.

we know for sure that the OEM exhaust flows extremely well. The restriction in your exhaust is all in the front half... manifolds, downpipe and CAT are your only REAL restriction WELL into the 13s and probably 12s

So I would only need headers if I wanted to play in the mid 13'* or lower? That still sounds a little strange but it works for me.

headers and a highflow cat, yes.

TransAmVille, your exhaust is mandrel bent 2.5" stainless tubing. It'* been that way for a LONG time on the Bonnevilles. From the factory, we have a superior exhaust to the Grand Prix.

I can think of MAYBE 5 cars on this Forum that have 'outgrown' their pipe diameter or mufflers.

My exhaust is all Magnaflow now, but it started with a catalytic converter going south (replaced with a high-flow), which **** it'* guts into the muffler (replaced with an F-body Magnaflow), and then added a resonator so I could stand to drive the beast.

I'm flowing more through the motor than most SSEi'* here, and I wouldn't sacrifice my low-end for any exhaust in the world. My current exhaust flows perhaps 15% better than stock, primarily because I ported my exhaust manifolds and went with a high-flow cat.

We've had a couple cars go with 3" too soon, and they lost low-end.

I waited to ditch the stock restrictive 2" dia twin exhaust pipes....it'* only 2 1/4" after the resonator, until after extensive mods. Fortuneately our newer SII engines have more aftermarket goodies to boost our flow.

I would agree. Your first move should be headers followed by HP CAT and then work your way back as you are able to decrease your Pulley size with other supporting mods. You won't be ready for the 3" pipes until you get down to at least a 3.1" pulley.

Just a correction here - I recently measured the stock downpipe on my '01 and it is actually 2.75". (my '95 was 2.5") The stock catalytic converter is also a different design than the earlier model ssei'*. I posed this question on another thread and no one seemed to know whether the newer models already come with a high flow cat.
I can say with certainty that you will lose bottom end torque if you do not match your exhuast flow with your engine flow. I recall seeing a formula on dynomax'* website that suggests pipe diameters as well. The exhaust is designed in order to keep the burned fumes flowing away from your engine and maintain velocity. If the pipes are too large, some burned exhaust fumes can actually re-enter the cylinder through the exhaust valve during the downstoke cycle and the performance effect will be like sticking an EGR valve on each cylinder in the lower RPM range.
One more important note when calculating the correct exhaust dimensions - the '01 exhaust design is very straight from the downpipe back. This equals efficient flow. I'm suspecting the cat may already be a high flow, if that is the case, I would not touch anything behind the headpipe unless you are producing some serious HP. Remember that the thing that makes our Bonnies quick is the torque. This is why even though some new Lexus may have similar HP, we can still take them in a drag race. I would recommend beefing up your transaxle so it performs the way it should before going nuts on anything else.

I'm refering to inside diameter. That'* what really counts with flow velocity. Your stock system is identical to what mine used to look like. The downpipe, if you remove it, is double walled for sound attenuation. The actual hole inside the stock rear exhaust manifold is only 2" dia where it exits. If you compare the difference between TOG headers and CI manifolds you would be impressed.

You are SC like me. You will gain torque as you decrease intake and exhaust restrictions....allowing you to install smaller SC pulley to match.