I've seen that article printed in different magazines (Turbo/Hot Rod) sine the 90's. More and more information gets added to it each time it gets printed but it's a very good article with a lot of excelent information. If you want more in depth exhaust analisys get the book Maximum Boost by Corky Bell. Corky is a VERY talented engineer who was a pioneer in early performance turbocharging and led the F1 development for several years.

Corkey Bell's "Maximum Boost"