RE: whats the different between tune muffler and tune pipe?
For gas engines that is. Jennings gathered all the information wandering about in the racing circles and put them in his book; a job well done. Gordon P Blair however is much more valuable reading.
Glow engines do behave a bit differently than gasoline or self ignition diesel engines due to the extreme internal cooling by the methanol fuel they burn. Take this into account when looking at flow efficiency and exhaust systems.