This is the only muffler that ive really seen around for my 97 2.8... is this a good price or a good company?

http://www.car-stuff.com/performance...amp;brand=2607

btw i was wondering if my exhaust would be too loud if i replaced both cats with a test pipe??? bad idea??

 

Wood_e just got a new Vibrant axle back for his '96 A4 12V. And mine is being shipped currently. Ask him how he likes it. And when i get mine on I'll let you know. Supposed to be a decent exhaust. I dont know anything about the test pipe stuff.

 

It'll be loud but that depends your tolerance. If you live in a state with no cat emission regulations and you don't mind the noise then go for it. If not then bad idea. VBO5 has a remus exhaust with deleted resonators and it sounds great, almost like a VR6.

 

i like the remus sound best

 

im gunna get vibrant axle back with punched out cats and ill try to get a sound clip

 

Keep in mind that punching out the cat on a naturally aspirated motor is likely to kill a lot of your bottom-end torque. You'll gain power and flow higher in the rev band, but down low your output is most likely going to suffer. Consider your typical driving habits before doing this, since you really can't undo it other than buying a new cat. If you drive around in powerslides at redline all day, go for it. If you're like most of the rest of us, you may not want to do this.

 

why would i loose low-end? im not over exhausting it.. what highflow cats do u recommand for the 2.8 in that case

 

A couple of different factors come into play, notably exhaust gas velocity and backpressure. There are some debates about the benefits of backpressure in the exhaust, but the main part is that a certain amount of backpressure can help you out because it helps with exhaust-gas scavenging (pulling as much combusted gas out of the cylinders as possible). Beyond a reasonable amount, backpressure becomes a hindrance, because it chokes the flow of exhaust gas out of the engine. On a turbo car, all the necessary backpressure is provided by the turbine side of the turbo, which is one reason why switching to larger downpipes or replacing a cat with a test pipe can make so much of a power gain (check out the power the 1.8T guys make with parts like that).

On a naturally aspirated car, however, the only source of backpressure is the cat. At low RPM, the cat's backpressure helps scavenge exhaust gases out of the engine, assisting it in power/torque production. At higher RPM, gas velocity through the engine can be enough to clear the cylinders on the exhaust stroke (effectively negating the need for backpressure), and at that point, when you're revving the **** off it, the cat is more of an impediment. That's why you'll see power gains up high with a test pipe, but torque loss down lower. Getting a larger cat-back exhaust system with smoother, mandrel bends helps in a slightly different way, because it allows exhaust gas velocity to stay high at high RPM (because it's flow diameter is larger, so it doesn't choke the exhaust stream the way a smaller diameter pipe would - think of using an OEM pipe at high RPM as putting 10 pounds of sh*t in a 5 pound bag, whereas the larger aftermarket exhaust means you're stepping up to a 15-lb bag - enough to work with comfortably). On the same token, its larger diameter can cause velocity to slow down at lower RPM, hindering the scavenging effect. That's also why many exhaust mods seem to make more power up high than they do down low - it's a combination of velocity and backpressure, and larger pipes/lower restrictions will alter these properties in different ways.

If you do want to go with something other than a factory cat, check out Random Technology - they're a high-flow cat that still scrubs enough to pass emissions (I've seen them pass CA emissions on the 300Z in the past, which I'd bet is a dirtier engine than the 2.8 for various reasons (older design, not as much electronic smog nannying, etc)). They've been dynoed to show HP gains within 1-2HP of a test pipe, but still able to clean the exhaust air. You'll still lose bottom-end torque, being that it has very little restriction, but you won't have to worry about passing smog testing, and it may be a little quieter than a test pipe (the test pipe may end up being too loud - it's subjective of course, but everyone has different ideas of what "too loud" means). You'll get your top-end gains as well, again because of the higher-flowing characteristic of the RT cat vs the OEM cat.

 

you don't need a muffler specifically for the 2.8L V6, you can get pretty much any muffler you want as long as it has the right inlet size (2 1/4" is stock ibelieve)...removing the cats is a bad idea because it'll cause your CEL to be on all the time and you definitely won't pass smog with no cats...you can do a 2-1 conversion and replace both cats with one center cat...there is also a resonator (mid muffler), but i recommend leaving that in. i took mine out and i was embarassed to drive the car it was so loud.