Conversion to old-school twin exhaust pipes

[jackronner]

I just love the burble of a big twin, but even with a Remus on my 2009 RT it just doesn't cut it.  I'm sure that twin pipes like the old Beemers had would present problems with back-pressure and the on-board computer, but has anybody heard of such a conversion?  I just want to sound like a motorcycle again.

[David.]

How about removing the silencer and fitting an exhaust tip.



This is a Camhead with the silencer removed,
https://www.youtube.com/watch?v=_mOOcqJYWnE

[jackronner]

Still, I don't think you can achieve the same rhythmic, alternating burble using just the single pipe.  I started the bike up with the silencer off once and was surprised it wasn't louder,  but also it didn't sound like an old beemer.

[David.]

How about ditching the headers for a set without a catalytic converter. With an exhaust tip fitted, it'll be a straight through system.

BMW R1200R - Fitting Arrow Stainless Exhaust Headers, https://www.youtube.com/watch?v=cBM6h6XIgl8

[jackronner]

Thanks, Dave. But, again, your video is just another 2 into 1 system.  I guess I'm wondering if, with a bit of modification, some pipes originally built for the old bikes with a separate silencer on each side, would be tolerated by the new engines/computers.  I remember hearing a nice note from older Beemers with what must have been aftermarket, louder pipes.

[David.]

I'm wondering if, with a bit of modification, some pipes originally built for the old bikes with a separate silencer on each side, would be tolerated by the new engines/computers.

My thoughts are, making significant changes to the exhaust system would be best checked out through exhaust gas analysis to confirm the fuelling.

At the risk of being shot down, re-mapping may then be required. The oxygen sensors may have to be retained, not sure if this is the case if the cat. is removed.

[bandytales]

At the risk of being shot down, re-mapping may then be required. The oxygen sensors may have to be retained, not sure if this is the case if the cat. is removed.

I would say that it would make sense to get the bike re-mapped to get the best out of it anyway.

[David.]

This article seems to concur with some of the thoughts already posted, https://www.denniskirk.com/blog/2018/09 ... omparison/

"With 2 into 1 exhaust systems, the two exhaust pipes combine to emit fumes through one muffler.  Sound will obviously vary depending on the pipes and muffler, but these systems are generally characterized as being higher pitched compared to true duals".

"When you make the change in your motorcycle’s exhaust, the work doesn’t end there. If you’ve succeeded in increasing the airflow out of your cylinders, then the fuel/air ratio should be changed as well. Without a change, your engine might run lean, and you’ll need to either re-jet or remap your motorcycle."

[RT in BC]

This article seems to concur with some of the thoughts already posted, https://www.denniskirk.com/blog/2018/09/19/2-into-1-system-vs-true-dual-exhaust-a-comparison/
"With 2 into 1 exhaust systems, the two exhaust pipes combine to emit fumes through one muffler. Sound will obviously vary depending on the pipes and muffler, but these systems are generally characterized as being higher pitched compared to true duals".
"When you make the change in your motorcycle’s exhaust, the work doesn’t end there. If you’ve succeeded in increasing the airflow out of your cylinders, then the fuel/air ratio should be changed as well. Without a change, your engine might run lean, and you’ll need to either re-jet or remap your motorcycle."

This was one of the aspects of my Moto Guzzi that I miss with my RT - nice twin chrome pipes and mufflers. Of course, they were joined underneath and had the O2 sensors, etc.  Simple 2 pipe system on the Norton, Triumph, and my /5, gives a balanced look.  I sometimes wish that the muffler on my RT was not so huge.