exhaust-1

	The SuperTrapp System Installed This photo showing the 2002 setup with 16 diffuser disks in place. The more disks you add the louder the bike gets but the more gas flow you have. The object is to strike a balance, more disks = more gas flow, more noise, more top end power. Fewer disks = less gas flow, less noise, more low and mid-range power. This makes the fourth exhaust system we have tried. This one seems to work the best for all around power, although the Ray Sumner megaphone produced tons of high rpm power when tuned properly. Very Loud though.
	Parts for the new SuperTrapp megaphone/silencer. About $100 bucks for this stuff. This unit fits a 1" OD head pipe.. but they do make one that fits a 7/8 head pipe (stock SL/XL Honda size). Comes with all the "diffuser" plates you need, all hardware etc. This is a clamp on model... I'll be welding it on though. It comes with a tuning guide that recommends 6 disks for a racing 70cc. I figure since there is probably no way they expect a 70cc to be modified as much as the CD-1a.. and the fact that it uses a 1" OD head pipe instead of the smaller 7/8" stock size that 8 disk will be about right.. that's what I'll start with and tune from there.
	Photo of the new Sumner megaphone exhaust built by Ray Sumner of Australia. It has brought the bike to a new level of performance. We are having some small problems getting the carb jetting to match the new pipe at lower rpms but this new exhaust has increased high rpm power tremendously. I think perhaps a megaphone of a smaller diameter, longer and with less taper might produce power at a lower rpm. I hope to come up with several different sizes and fabricate an adapter so they can be interchanged on the head pipe.
	I have deleted all the information about the home built exhaust I was using in previous seasons because.... my home built exhaust sucked! This is what I have been using since the 99 race season. It is the stock Honda exhaust from an early 70's Honda SL70 dirt bike with the internal baffles removed. Sounds good, seems to produce good low rpm power. Hopefully in the near future I will be installing a Takegawa or Kitaco race exhaust system.