tuned length exhaust

[V8Pinto]

Has anyone experimented with tuning exhaust length? What about different header tube diameters?

I found an online calculator (kinda Harley focused) - anybody have something hiding in their hard drive that helps optimize an exhaust for top speed?

[V8Pinto]

Here's the link to the Harley calculator

http://www.nightrider.com/biketech/calc_exhaustlength.htm