Here is some tuning Information you may look through...Just some bookmarked sites I have come across:
http://www.osengines.com/faq/faq-q652.html
http://www.rcaerobats.net/tuned_pipe_info.htm
http://www.jettengineering.com/tech/pipetune.html
http://www.macspro.com/tuning.asp
http://www.mh-aerotools.de/airfoils/...pe_main_en.htm
http://www.prestwich.ndirect.co.uk/tunedpipetheory2.htm
http://rcboat.com/pipe.htm
http://www.*********.org/cars_eng-tuning.htm
http://www.bmaps.net/info/pipes.html
http://engine-analysis-software.com/pipe.htm

Sorry for the Information Overload..he he

Maybe you will find some useful information in there?? I realize it's not engine specific...But hope it helps anyhow??

Have Fun...

Chuck