Tuned 2 stroke pipe volume formula

[buzbikebklyn1]

Does any one know the method/formula that you would use to determine the size and volume of an expansion pipe for a particular engine?
BBB

 

[Goat Herder]

There is so many links come to mind I thought of this one. http://motorbicycling.com/f51/expansion-chamber-resonance-25085.html