MP3 of S5 N/A RX-7 Exhaust for the Curious
 

Stock Exhaust Manifold (nonturbo)
Bonez High Flo Cat with Presilencer
Stock Style Dual Mufflers

The file was recorded with a cheapo $2 condensor microphone and a laptop with the microphone about 2 feet from the exhaust outlets. What you hear is going from idle to 8k RPMs at wide open throttle (WOT) while in neutral.

I seen a number of questions about what different exhaust combinations sound like, so I thought I'd post mine for fun. It actually sounds a little less high pitched in person, so I think the cheap microphone is not picking up the lower frequencies too well.

---Enjoy

With the NA's exhaust, the header is the big deal.
It's a trade-off, you get more power, but with more loud.
Either buy or copy the RB design.
The cat will tame the loud nicely.
Don't go too big with the mufflers or the tone will get tinny.

Here's a sound file of my old "barn in the woods" muffler shop made setup.
link to mp3 file

Bass Adjusted Version
 

I increased the bass by 3 dB (below 200 Hz) to make it sound more like it does in person to account for my crappy microphone. I used a program named audacity under Linux to do it (along with the "lame" mp3 encoder).

thats pretty quiet.