Megan midpipe with a skunk2 universal muffler?

Good for what? Performance? lol...it'll make a lot of noise, that is about all it will be good for on a stock Honda Civic Si.

@John...where are you getting your 8hp gain numbers? Have dyno's to prove it? I'd be willing to put money on the fact that any horsepower gains would be purely on paper, pretty low and of negligible effect on the actual performance of the car. 8hp is not happening on a stock K-series motor, sorry man...that's the kind of literature they throw at consumers to get them to buy their exhaust kits, without supporting mods, exhausts on these motors (and any honda motors for that matter) simply do not yield legitimate gains.

I have 4-1 Stainless headers going into a Megan Test Pipe with a Universal Muffler on my EP3 and it sound awesome. Nice, deep purr as well as solid. Even when you Gun it. I also have a 3inch intake with a 8in cone (custom). With both together my red line went up to 7500 before i adjusted rev. You will get some more top end power but as far as low end power forget it. Im getting prob an extra 8hp at the most. Remember, its a K20A3. Its like the redheaded step child of vtec's. You wont get much more out of that block. However A3s love boost! Hope this helped.