Cats don't control the volume of your exhaust that much. Its mostly the resonator in your catback and the diameter of all the piping. It will definitely be louder with a whole 3" system, but I found with the dp it was only louder than before when I was accelerating. Before I had the dp, I just had a HKS catback.
from what i've heard on cars, catted is a good bit quieter...russel (strayen) as a 06 like mine. He has an invidia catted dp and i have an invidia catless. Now our exhausts are very different, mine being a much louder n1 style megan piece, his being a more mellow greddy evo2. But my car is very loud and has a couple pops and gurgles when decelerating. And you can hear mad turbo spool all the time, almost like a semi, which i think is awesome. From what I've heard of his car, the turbo spool is louder but overall everything is much quieter and very mellow especially if you're NOT getting on it. Almost like stock. With mine, even the slightest blip of the throttle causes the turbo to spool up and exhaust to get pretty loud. just read clemsonscooby's post.... I do think the exhaust has a lot to do with it. But my n1 was pretty mellow and had a nice tone to it and I could make it quiet when i wanted by not putting as much pedal into it. But when i changed to the invidia catless it got loud. still has good tone but when you open her up it is a whole 'nother beast. I need to do a comparison with our two cars with some audio/video
we should meet sometime next week and actualy listen...cuz mine..is ..loud and I have g200 and catless dp..im afraid of putting in a catless up..... Maybe im not use to it...I heard ppl saying G200 in't that loud. But to me it sounds like a freakin rocket.
Exactly...I was hanging with russel (strayen) last night and when he left he babied it and you could barely hear the thing. But I've heard him give it some stick and it sounds awesome...very controllable volume.