budget sv650 cafe racer

[gt alex]

The dba meter arrived today the staintune muffler that came on the bike measured 84dba at idle and 98dba at 5000rpm so it looks like it will be a challenge to find a shorty that stayes under 94dba without being to restrictive. I thinking  dual mufflers might add some volume and each one could be more restrictive because they would share the flow.
Best shorty tested so far is 89 idle and 100dba 5000rpm.

[gt alex]

I have been playing musical mufflers. The staintune is gone and I have settled on the short muffler from my old VW kombi. Getting the sound and baffles right is still on going. I have been thinking of fitting discs a bit like supertrap style

[gt alex]

Just doing some more testing, making disc baffles from drain strainers. By lining up the straining holes a spacing to let the exhaust through and then using the theads on a central bolt to space them evenly approx. 1/2 mm apart and blocking the end (just with a rag for testing.)
It seems to work well, Im just not sure if relying on the center hole will be to restictive WOT. I don't think it would be worse than other DB killers plugging the end.
With this layout I could use 1/2 mm thick washers for consistant spacing. I only had 5 discs but back pessure and sound seem on track.

[pidjones]

Interesting. I tried one washer covering ~ 50% of the area ~1" after the baffle on each side of my GL1000. Held in place with large pop rivits to three 1/4" tubing sections each. Within ~ 40 miles it spit them out. Ripped the large pop rivets right out.