Whenever I see the RB exhaust mentioned, it's never specific which exhaust. There are three exhaust systems on the Racing Beat website:
1987-91 TURBO REV II Complete High Performance Exhaust System
1986-92 Non-turbo Street Exhaust System
1987-91 RX-7 TURBO II Cat-Back Street Exhaust System

I'm aiming for something very subtle and quiet. I'm also assuming that "RB Exhaust" refers to the latter two; am I correct? And is the difference between the exhaust in terms of sound noticeable? They're different when it comes to performance, of course.

Additionally, my car is a 1991 NA FC, but I do plan on adding a turbo to it down the road. This won't happen for at least several years, however. Should I bother with the turbo exhaust system or should I stick to the NA until I turbo it?

Thanks

 

The turbo vs. non turbo exhausts are totally different. Turbo exhausts have a different downpipe and silencer, larger mufflers and larger pipe all around.

All of the RB exhausts are very high quality. You are going to get an increase in noise more so on an NA then on a turbo model. But RB has worked hard to keep it tasteful and you'll be happy with the result.

 

The REV-TII exhaust is a 3" system that replaces the stock precat and main cat with a downpipe and presilencer. This is in addition to the cat back portion. You can't bolt this onto an NA because a turbo downpipe doesn't go to the same location as a NA.

What you want is a 2.5" header & presilencer, and either the NA or turbo 2.5" catback system. The advantage to going with the turbo catback is the mufflers are 2.5" inside instead of 2" on the NA system. This will be a little louder, but more cost effective if you decide to run a turbo motor later.

You can go with just a catback system for now, which will bolt up to the factory main cat, but there will be a .25" difference in the pipe size (2.25" stock), so getting a tight seal will be tough.

 

So am I correct in assuming that the turbo RB exhaust won't fit on an NA? Or is it just not worth doing?

 

i'm wondering the same thing with you, what should we do?
i'm planning on making my 90 n/a turbo somewhere down the road
what would you guys recommend doing?

 

No, the turbo exhaust will not fit the NA. The catback will though.

 

it can be done as long as you do some cutting and welding. I did this with the RB TII exhaust I bought almost 2 years ago because I got it for soo cheap. It's connected to my RB header. Most people, however, won't bother doing this...

 

And what's the difference in sound between all three?

The NA catback will be louder than the turbo catback? What about between the turbo catback and the REV II?