Cat back turbo back
 

For turbo cars can you use the same muffler thats on your n/a engines? I will be turboing my car in the future but for now I want an aftermarket muffler is there any that I can use for both systems. Which will work well

Enthuza 3"
If you're spending the money you might as well give yourself all the headroom you'll need.
2.5-2.75 would be fine as well. Depends on budget and who you're buying from.

Generally speaking, the turbocharger itself acts as an extremely effective muffler. The SRT-4 for example, doesn't use a muffler... I think it's got a couple expansion chambers to keep the noise down. Using a muffler designed for turbo applications on an NA car will be VERY LOUD! Using an NA muffler on a turbo application will be quieter than stock... but the muffler will be more restrictive and you'll sacrifice a small amount of power.

I've got 2.25" Borla Duals installed well before I decided on boost... and I'm probably down about 10-15whp compared to a 3" system. But I'm also running a test pipe in place of a cat to help compensate. I'm not all that bummed though... as QUIET=STEALTH, which I'm all about.

you're probably down a lot more than that sam. remember, i did minor headwork and the 3" enthuza vs. the borla dual and picked up about 40rwhp at the same boost level.

http://www.boostedmiata.com/dynos/scott_vs_exhaust.jpg

^ Woh. Guess I wont be running my stock exhaust for as long as I thought.

Brain: What boost was the dyno done at?