For information only - this is why your factory exhaust sounds so crap.

It uses the same shell as all the Toyota-engine installs. Interesting to see the end-cap seams welded up - different from the old 111R silencer which had rolled/folded ends. Obviously more back-pressure to deal with on this supercharged install. It has a double-skin to control drone on such a large open chamber. Makes for a heavy unit though - 16.4Kgs.

Looking at the internals, it's a typical Z-flow arrangement helping to control NOISE emissions. Each end has a double-walled chamberfilled with stainless wire, again to help control drone. Early 111R silencer had fibreglass filling but it used to melt into little glass balls!

The entry pipe is reduced from 63.5mm to 57mm, so quite restrictive for a supercharged motor. The reverse pipe is 60mm and the outlet pipe is back to the full 63.5mm. You can see the entry to this final pipe is not straightforward - gas-flow has to come back through the mesh screen. Holes punched at the entrance of that pipe increase the area for gas entry. All features to help break up/disrupt the sound waves/energy.