If you want a quiet exhaust get the RB turbo back. It makes ALOT of power for an exhaust system and its just about as quiet as exhaust but it has a deep tone. Almost makes it sound like a nice exhuast on a piston engine. And it has a conservative look good for making a sleeper. It's tight... tight like a tiger.

yeah i want it know. I dunno too much about the design i really like the n1 design but knowone know rx7's like racing beat right