2 into 1 for Sidecar Outfit

[ngthomas]

Howdy,

My XS650D/Velorex sidecar project is progressing. The wheels have been built and are awaiting shipping from the builder.

I have been buying parts I know I will need and holding off on some parts till I get the engine apart etc to see what needs replacing and what can be used.

As far as the exhaust system goes, I had a custom 2 into 1 header built that goes out the left side, low. Now I need to find a muffler. I want to improve power and in fact I have the 750cc Big Fin Big Bore kit from Mikes. I am going to get the crank and cam rephased (277) also. Will probably run the BS38's that were on the bike. Obviously I would like to improve flow, but peak power is not a concern. I am after improved power and total reliability since I will be taking my Wife touring on this outfit.

At the same time, since it is intended to be a touring rig, I don't want it to be uncomfortably loud. As always there are conflicting goals and tradeoffs will be required :-\

Does any one have any suggestions? I suppose I could temporarily block the crossover and use the stock muffler ('77) on the left till I find something but I would like to have all the bracketry in place before I send the frame out for powder coating.

I would like to have a chrome muffler but could also go with black (the paint scheme will be chrome on black). How about the tunable mufflers like the Supertrapp? Can these actually be stopped down to where the sound is minimal and still make adequate power? I suppose if they are easily tunable, I could run it a bit more open for weekend rides and quiet it down for long trips. Does it adversely affect the carb jetting to change the number of jets in these things?

While cost is not a big concern I don't want to spend $1,000 on a muffler. My wife is already gonna crap when she see's what I am spending on this thing :-O

From a looks point of view either a low muffler or an upswept muffler could work. I was thinking of adding a fish tail (a la Velocette) to the tail pipe so that gives you an idea of where my tastes lie.

Thanks,

Nelson

[5twins]

2-1s can be difficult to tune for, especially if your headpipe diameters are larger than stock. Larger pipes move the power band up in the RPM range which is exactly what you don't want. You may need to add inserts both at the head and down at the 2-1 collector to remedy this.

To make it quiet, the muffler will probably need to be big. My advice would be someone's discarded stock muffler used from eBay. You could probably pick up one of those newer cannister style cheap. I would match your collector pipe to the muffler I.D. Those adapter inserts always leak.

[ngthomas]

Howdy 5twins,

Thanks for the info. I know I can get the inserts from Mikes XS for the header end. I am not sure about one on the collector end.

I am leaning towards one of the Super Trap internal disc mufflers so I can adjust the muffler for sound level and power curve. Super Trapp also has a "fishtale" tip.

Nelson

[headcase]

From your comments on an earlier post, I would think your wife might not fuss too much about the money spent once she gets back out on the road in that sidecar. Just make sure the ride is good for her and I bet she'll hand over the checkbook without even remembering

[sprkeyez]

I was thinking to..But clear me that all the parts are being prepared on order separately?