More info on the system, by Jim Rothe (very nice article)
http://www.jimrothe.com/mazda/exhaust.html where he compares this to the RB...
Here's a little snippet from the article:
"Mindtrain has many systems for 1st gen's, including racing and streetable exhaust systems. True to their word, their exhaust systems use a larger diameter piping than others, including Racing Beat. That should make for a slightly more free-flowing exhaust. (Laws of diminishing returns apply here, so I can't say that there's really more power on tap than with another manufacturer's exhaust system. But MT claims their system has more flow potential, and that seems reasonable.) The tubing is a very heavy gauge steel -- certainly the thickest I've ever seen on either a car or a truck. The "Big Throats" muffler is also the coolest looking muffler I've seen on any 1st gen RX-7, with large, twin chrome tips. (That was in '97. Current Mindtrain mufflers have polished stainless steel tips.) These qualities will probably be the same on all of their various exhaust systems."
"This is such a heavy duty exhaust system that I'm sure that it will be the last one that this car will ever need. (I've since transferred this exhaust system from my old '84 to my current '85, and every component is still absolutely rock-solid, with only slight surface rust. This is the rust-belt Northeast, you know.) Considering the system's longevity, it was money well spent."