Modern Vespa

I need to buy a silencer for a SIP/Nordspeed R2 and wondered about the impact of can length and perforated tube ID on performance and noise level. I'm looking at the MMW RS2000, which comes in either 300 or 350mm can length and either 26 or 30mm perforated tube ID. I'm assuming that a longer can and narrower tube allows for more insulation wool, so quieter, but is there any downside from a performance perspective? Motor is ported MHR 210/221 with MRP head, reed induction and 35 AirStriker carb.

Edit: also interested in how the different sizings might effect heat build up and dissipation. Greater perforated tube ID better?

Very good question…!

Didn't know they came in mmw came in different sizes. But the 3 bolts on the cap is smart…

I imagine go for "same diameter as your stinger"…

I'd have assumed you'd want to match the tube diameter to the exhaust output diameter.

I'd love to put a quieter can on my Smallie. What it has now is pretty ineffective.

Need to change the glass fibre stuffing after all that carb jet testing

The silencer baffle tube must not be smaller diameter, than the stinger, unless that's the intention, then its fine.

Thanks all, makes sense. The 'stringer' on the R2 has an ID of 25mm, so the 26mm baffle appears to be the best match. Any further views on can length, other than aesthetics and possibly lower dB with a longer can?

Would make sense if a longer silencer would be quieter.

I know for sure wet exhausts make a noisy endeavour. And a light one too, to
minimise stress cracks in the metal.

I have this one on my 221. Several years already.
https://www.sip-scootershop.com/en/product/silencer-s-s-newline_20007AW

I have a bunch of these too. Spares from buying exhaust from Scooter & Service.

But they weigh in at 1.1kg, cracked my curly exhaust and I ended up swapping to SIP carbon silencer which weights around 550g.

Wonder if I've lost any power along the way not using the new line silencer…?

Not taken it off for a long time. Don't remember it being that heavy. Stock S&S is stainless? These are the full welded aluminum version.
This is the fourth silencer on the same pipedesign exhaust. First two were sip carbon, third sip aluminum, all fell to pieces at the rivets and or the bolts broke free. Scooter does do near 10,000 rpm very often though.

Cracked exhaust was steel, exhaust I have on now in the 210 is double wall stainless.

Yeah the full welded aluminum version, looks great but did put it on the weighing scales because it felt like a brick.

Yeah, can definitely feel the quality of it. Really made to last. Guess they were needing one that didn't break for themselves.