2 into 2 exhaust system

[radrod]

Are there any 2 into 2 exhaust systems for this bike? I see many 2 into 1 systems. And I see others where they are 2 into 1 then ported again to 2 cans. But i am looking for a true 2 into 2 system where the gasses from each header never mix together.

Anyone find anything?

 

[radrod]

Anything???

 

[alimey4u2]

Not seen anything.....

 

[AdamA]

But i am looking for a true 2 into 2 system where the gasses from each header never mix together.

Why?

 

[boarder]

Why not ?

 

[Schtum]

Why not ?

Because GSes are about function. Even if it's just a matter of aesthetics, then the prevailing one where GSes are concerned is a functional one. There's no reason why a 2 into 2 system should offer any functional advantage over a 2 into 1. Ergo.......

 

[AdamA]

Why not ?

Because different configurations have different effects on the engine output.
I assume some thought went into choosing the 2-1-1 configuration so enquired as to why the OP wanted 2-2.

k?

 

[ts2]

I'm no mechanic

but I thought that you wanted the gases to mix, as the pressure wave from one cylinder causes some back pressure at the other, effectively helping to seal the valve. From what I've read (ie don't take my word for it), the exhausts are tuned so that the back pressure hits the cylinder just as the valve is about to close, thus helping keep the fuel/air mix in place. I guess if you had two exhausts you would effectively have to tune them like two single cylinder engines. It obviously can be done, but I'm not sure I can see the benefit.

Anyhow I'm a biochemist, who reads too much and thinks he knows more than he does, so take all this with a pinch of salt.

TobyS

Oh, and I take it you don't plan on carrying luggage. Otherwise you'll have to have an underseat end can (or two) to fit the current systems? Still if you want it enough, there's bound to be a way to do it. TS

 

[Wapping]

There was a thread on UKGSer about an underseat exhaust for the 1200GS. A search should turn it up. I guess that ran 2-2?

I can't see much point in running 2-2 unless it goes under the seat. You will have problems hanging the second exhaust down the offside of the bike, which will reduce luggage space.

There again, I can't see much point in a 2-2 anyway.

 

[ts2]

Oops

I think I got the wrong end of the stick. The tuning of the headers appears to be more to do with the last pulse helping pull through the next one
http://www.nsxprime.com/FAQ/Miscellaneous/exhausttheory.htm (see the part on "The Exhaust Pulse", though who knows who wrote it).


Anyhow what do I know.

TobyS

 

[alimey4u2]

The most effective system for twin cylinders is the one designed by Dublin University ( if my memory serves me well) for Paul Dunstall, which was 2-1-2...

 

[AndyW]

but I thought that you wanted the gases to mix...

which is why 2-2 systems usually have a balance pipe between them (to some extent giving the same effect as 2-1-2).
I'm no engineer but I guess for some engines 2-2 would be less restrictive than a 2-1-1 or even 2-1-2 system, i.e. higher rate of flow through overall higher volume exhaust pipes? I imagine that only highly tuned motors/high revving motors would benefit.

There was a thread on UKGSer about an underseat exhaust for the 1200GS. A search should turn it up. I guess that ran 2-2?

here ya go:
http://www.ukgser.com/forums/showthread.php?t=93703&highlight=underseat
...........2-1-2

 

[radrod]

Thanks for all your replies. I was just seeing what was out there. It is not so much of a performance upgrade i look for, but more for developing a stereoscopic sound like some of the other great 2-2 twins.

 

[blobbs]

Have a look here http://www.motorcycleinfo.co.uk/index.cfm?fa=contentImageGallery.listImages&directoryId=2342. 4th photo down on the left (and the middle)