4 in 2 in 1 with a flat collector which go along with the bandit sump ( for ground clearance ) and handmade from a friend
and a marving mot (legal) pipe , and the rest of the time with the marving race
There is a guy on the german KOC Forum who does the efe / Pop conversion at the Moment
worth a look
http://www.katanaownersclub-forum.de/viewtopic.php?f=35&t=2964