Performance Mufflers vs no mufflers

I have a 96 Mustang GT 4.6L. In PA, state inspection requires mufflers. As it stands now, my exhaust system consists of Catalytic Converters and straight pipes out the back. The Catalytic Converters keep the db's down enough that it just doesn’t seem right to use mufflers at all. I just bought the car. The pervious owner lived in VA. It passed PA inspection because the mechanic did not check my exhaust system carefully, so I have some time to make my decision about what mufflers to buy.

I am running 2 1/4” pipe from the Catalytic converters back.

I’d like to get some input from other Mustang owners. If anyone would like to post his or her recommendations, or opinions I would appreciate your input. I have heard some positive opinions of “flowmaster” and “hooker” mufflers in a previous post that I placed in the General Discussion section of this forum.

well, flowmaster or borla come to my mind here. i never knew Pa required mufflers. o well i guess ill keep mine on.

Well to be quite honest with you, I'd stay with no mufflers. I used to run cats only here in Minnesota back when I had my 88 GT. We used to have inspections then too, and I never once had any problems. The thing is, most of the people at the inspections places aren't the brightest. Unless you get someone who is fairly knowledgeable, you they probably won't say anything. And even if they do, just tell them that one set of converters is actually a special kind of muffler. Most won't know the difference.

Worst case scenario, they'll call you on it and you'll have a month to fix it. Best case scenario, your car keeps sounding like the bad ass it is

I have always used Flowmaster two chambers. They give a nice low rumble and compliment the Ford V8's very well. A friend of mine put a set of Flowtech Afterburners on his 88 GT. They produce a good quality sound as well. I have also been told that the Hooker Cat Backs are awsome as well, but they work best in a balanced Hooker Setup.

As far as going without mufflers, it is my understanding that the Ford 4.6 Modular Engine (96 on) requires exhaust back-pressure for optimum performance. I may be wrong on that and it wouldn't be the first time. The catalytic converters are a must or the O2 sensors will go nuts unless you make some computer mods. My recommendation: Flowmaster Two Chambers with Turn Downs.

Flowmaster 2 or 3 Chambers, also use Turn downs and point them out the side - Much better sound.

I decided to get the American Thunder Cat back system from flowmaster. Thanks for the input.

what is the advantage of no mufflers?
thanks

Quote:

what is the advantage of no mufflers? thanks

Honestly, Im not sure. Maybe a unique tone? I would think it would be a disadvantage because of less back pressure. Anyone else answer this??

Generally speaking, unless you are running a big HP engine, you should be running mufflers in order to maintain proper back pressure. Without back pressure, your power really only can be achieved at higher RPMs and unless you are launching at high RPMs, running without mufflers won't help you performance-wise because you'll have no bottom-end/off-the-line power. It does add a nice sound, though.

The Modular Motors do require backpressure as do most stock ford smallblocks. With the variety of mufflers available, find the sound you want and buy it. They all perform about the same. If you want more horsepower, The biggest robber is the stock cat H-pipe followed by the headers. Change the stock cat for a High Performance / High flow Cat. The high flow cats barely restrict flow at all. then go with a good set of headers. If running unported heads 1-5/8 headers will be plenty.