Wow, little Charlie is bouncing back better than ever (he would have been feeling crook for a while before he crashed), and today, in between discouraging Charlie from running around the back yard barking at birds, I found my passion for progress on the Civic returning. I'd been searching for ages for some pieces of stainless I cut from my muffler when I reopened it recently for 'mods'. Anyway, I finally found the bits I needs to weld the muffler back together, then sand and polish back to new again.
Internally, I removed the baffling and compartments, then I welded a piece of 1-3/4" stainless perforated tube between the outlet and inlet, this 'bypassing' the compartments, and creating a straight-through design muffler, with ultra-thin stainless swarf (which I bought in the form of stainless scouring pads at the supermarket -- LOTS of them). I found with my bike muffler, if you pack the muffler really hard with the stainless pads (not Steelo!), the weight/mass of the packing absorbs heaps of sound at low revs, as in, the muffler is way quieter than other straight-through mufflers I've heard, which are really boomy down low. Anyway, I'm hoping I get the same result with the Civic. The muffler doesn't weigh any more than one with glass packing, but the stainless works better IMO.
So now I'll have a nice sports-note coming out of Civic, especially when I open it up.
I hope to get it closed back up and looking like new in the next few days with a bit of luck.
I should say, this was a Genie Turbo muffler that I cut down on both ends to shorten it to fit the Civic. The muffler design was a hybrid straight-through/compartment-style muffler, with 50% functioning as a sports muffler (giving it a nice note), and 50% functioning as a conventional-style muffler, taking some of the noise out of the equation. Anyway, I only had the remove the baffles from the centre section of the muffler, because the ends are already straight through in design.