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View Full Version : Single cylinder -- 2-into-2, or 2-into-1?



xwhatsit
19th January 2007, 23:39
Hi guys,

Once my engine is all back together, I want to do something to the exhausts (the existing ones look ugly and rusted, and are on their way out anyway). Well my bike (CB250RS) is a single cylinder, but it's got that funny two exhaust trick. I have a spare set of (also fairly munged) exhausts, and I was thinking about cutting the silencers off those, and bolting/welding a pair of those Taiwanese reverse megaphones that Bonez has mentioned a couple of times onto the headers. (Edit: how do I mount these suckers onto my bike, anyway? Do I weld some mounting tabs onto them, and bolt it to the pillion pegs like the existing ones?)

However, I know a lot of people in the UK used to use a 2-into-1 system when replacing the silencers on this bike. This would also make better sense in terms of weight, and the fact I only have to buy one silencer. However, I like the look of the two pipes, and there's also the fact I've got to somehow procure a 2-into-1 header.

Is there any technical difference between the 2-into-2 and 2-into-1? In terms of how the engine reacts? Backpressure? Thanks.

ZeroIndex
20th January 2007, 02:45
2 into 1 will have slightly less weight... doubt you're going to be worrying about back pressure on a CB250RS...

xwhatsit
20th January 2007, 11:06
Hmm, OK, cheers. That's what I was thinking -- it's not as though you've got two cylinders with alternate exhaust strokes causing some kind of interaction.

Now I gotta work out how to convince my Uncle with a gas cutter and welder to make a manifold for me :D