I modified the muffler on my Echo CS-400 Chainsaw, mostly based on recent recommendations provided by many individuals posting in other threads on this forum.
However, I thought it might be interesting to quantify the airflow differences of the mods using a Superflow SF-110 flowbench. You can see how the various pieces of the muffler contribute to the airflow results, as well as a direct before/after comparison. The attachments tell the story.
I have a powerpoint file of all these attachements if anyone wants a copy.
Enjoy! Comments welcomed/appreciated.