I was wondering on the mazdaspeeds...
what is the size in diameter on the exhaust?
How many cats? resentators? mufflers? are on the car?

What exhaust system would you all recommend?

Please let me know. Thanks for all your help.

 

The stock exhaust is like 2.5, I had a place do a custom exhaust up to 3 inches. I had them remove the resonator or the second cat. If you have emissions test, it will pass. I live in northern VA and they are pretty strict about that stuff. The job will let your turbo breath a bit more and also sound pretty darn cool too.