I'm not sure about the power, but it will get louder. Last year my buddies and I got bored over spring break and decided to straight pipe my winter beater (77 Buick estate wagon w/ a 350, lol) First we took the exhaust off after the cat, and it sounded almost the same. Then we took the cat off and ran one pipe all the way back and Y'd it with 2 chrome tips out the back (lots of work for a car that only cost $150, but the looks I got were priceless, plus we did the exhaust for free) Any way after the cat was off the thing roared, It also rapped down nicely after it was revved up high. Man what a beast of a car.