I am interested in designing an exhaust system for a race car, and was wondering if anyone could explain the theory behind exhaust design. I am wanting information more along the lines of back pressure, scavenging, sound/pressure waves, gas laws, etc.

I am interested in designing an exhaust system for a race car, and was wondering if anyone could explain the theory behind exhaust design. More so on the lines of back pressure, scavenging, sound/pressure waves, gas laws, etc.
If you're not interested in gas theory, why are you interested in designing an exhaust system?

This is such a large subject that I suggest that you read a book about it.