Actually, with a performance exhaust already installed I would think the different from having a little extra silencer and none would be a difference of maybe 3-5 peak horsepower at most.

 

Don't get a rice can and you won't have that problem. I never understood the advantage of having a muffler with an outlet thats bigger than its inlet. The only thing that does is make a bunch of (usually annoying and high pitched) noise. If you want a performance exhaust that will sound good then get a Dynomax straight through muffler, not the Turbo muffler. I had one on my car and I loved how it sounded. It gives the car a much deeper rumble and looks a lot better than a can does too. One of my friends also put them on his Lexus SC400 with straight pipes and it sounded badass as hell.

 

Why Not A Free Flowing Flowmaster Performer Series 40 For Loud 20 For Quiet?

 

I think Drew is probably right. For a turbocharched car a straight through Dynomax like the bullet or ultraflow would be ideal. And when I said turbo muffler I didn't actually mean "turbo muffler." I meant a good large diameter muffler that will work good on a turbo car.

 

Yeah, that's pretty close to what my Prelude had dynoed with the silencer in vs. out. The spread was about 7hp. When I swapped the system out for an Apexi WS (MUCH quieter!), it dynoed right in the middle of the spread of Tanabe.