sorta..

without painting an entire page I'll say this:

think of your exhaust system like a conveyor system, which carries each individual breath (pulse) of air from your heads to your exhaust tips.. they all work together.. or, should..

the manifold/headers get really hot.. which is expected, and is good.. the hotter the better, because it will dissipate downstream as it goes.. each pulse of air is hot, but instantly starts cooling as it is expelled.. many folks wrap their headers with tape, or ceramic coat them, or some such and think this is because you want a cooler engine compartment, but this is just an added side bonus.. you really want them hot, and hotter than the actual pulses being pushed by the engine..

when air cools it becomes more dense.. a cool(ing) pulse is heavier than the pulse ramming into it, and harder to move.. you don't want that to happen.. you want to remove the cooling pulse as fast as possible to make room for the one behind it.. this is not as easy as it sounds..

you could have really BIG primary tubes (the tubes that represent each cylinder port), but they would soon fill with wads of cooler air that loses it's momentum.. so, you use smaller pipes which get hotter, which creates a vacuum due to lower pressure on the trailing end- that vacuum actually draws the next pulse as it slows.. this is what is called scavenging- which most folks call 'back pressure'.. you WANT as much scavenging as possible, you want NO back pressure if you can't help it.. but it is hard NOT to have w/ emissions being a LAW..

bends in the pipe, Y/H/X pipes create back pressure as they restrict the movement of those pulses.. (an aside: THIS is the issue with the OE Y being the worst dang Y on the planet, it creates BACK PRESSURE, which works against free flow and scavenging)..

a catalytic converter placed in a strategic location is a good thing in one way: It creates an area that is MUCH hotter than the pipes coming in and leaving it.. which promotes scavenging.. it produces SO much heat, in fact, that the use of a high flow cat's inherit restricting catalyst is actually dang near negated.. it is a good thing for this reason that the cat is directly behind the most restrictive part of the OE rig: the Y..

what happens after the cat: the air is hot again.. dang near as hot if not hotter than it was as it was expelled.. which is good, because now it has to negotiate the muffler..

mufflers are likely the second hardest place to push the pulse through, as they don't have the advantage the cat has by being as hot.. so, a good flowing muffler is a good choice.. Hammer, over in the third gen section has a GREAT write-up showing the different flows to be expected from different mufflers.. an example: FM's, in short, aren't much better flowing than stock- though they sound bad-***.. so, you'll be making a choice here.. performance, sound, or a balance?

one in two out mufflers are popular because it appears to be dual exhaust, and it sounds good, and it's a lot cheaper and less tricky than true duals.. they usually flow better because you are in effect doubling your exhaust size behind the muffler, and the muffler has a more efficient means of expelling the cooled pulse.. so it's better.. but not that much better..

it's all about keeping it hot, but not using so small a diameter pipe that it restricts.. and keeping it open enough not to create back pressure.. but not so open it doesn't get hot enough to create that magic scavenging..

you're armed now with just about all there is to know about exhaust, save the diameters of pipes and equations based on head/valve flow, and such... You're doing a cat back exhaust, with the added bonus of ridding yourself of the OE Y.. THAT will net you gains you will feel (and not just hear).. It will come down to the sound you're looking for, and how much performance you're willing to give up for that sound.. or the balance between the two you choose to have some of both..

I highly rec magna flow or Bora mufflers.. they don't sound as good as others, but they floggin' FLOW.. just my opinion though.

 

how does one get rid of the y pipe

 

Sawzall.

 

ha can do thanks squirrels

 

I went with the Magna-flow direct fit replacement cat and a Flowmaster 40 series muffler. I then had an exhaust shop run 2.5 inch pipe out the right rear and left single exhaust. Like you I did not see much point spending extra money to run two sets of pipes out the back. I also added the SCT tune from Hemifever and I love the way the pickup runs! A very much needed performance boost and worth every penny.

Jeff