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.

[gt alex]

I got a bug and was out off action for a week,I still have to weld the exhaust, but parts still arrived the bango switch for the rear sets. unsure which thread my year sv had I ordered both 1mm and 1.5mm pitch at only $4 each still good value and I won't get stuck. The other thing that arrived which won,t be fitted till the hump frame is going on, the rear shock, fully adjustable comp & rebound 8mm shorter than standard so I will need to revisit the rear height. spring rate still unmeasured.
Also the harley dropin lowering kit arrived I hoped the main spring would be about .95kg/mm but is is so stiff I didn't even bother checking(spares)

[gt alex]

pictures of above

[gt alex]

Today I fitted the rear brake bango bolt switch. and fixed the way the rear brake line was run. Because the rear sets changed the mounting angle of the rear master cyl. The brake line at the master cyl end kinked the line up after fitting the rear sets so I just rotated the line so it would point along the swingarm. Since it fitted both ways I may get a straight fitting when I change to a braided line.

[gt alex]

Today I welded the muffler to the center pipe I cut from a staintune (used 2.5mm 316 stainless rods with a inverter stick welded the linished with a flapper wheel) and modded a double barrel dbkiller I made as an experiment. I added a end plate and cut slots with a grinder and packed it with stainless steel wool. the dbkiller was ok before the mods 105dba measured 1/2 metre from pipe 45deg @5000 rpm with mods it dropped to 100dba. Will do if the disk baffles don't pan out