Interactive exhaust valve

[VTR1000F_imp]

What is it? I read in some CB1100 review that stock silencer is equipped with such valve. What is its purpose and how does it work? Education time for me! Thank you!

[Lord Popgun]

We don't have it in the US. I can't remember what its for though.

[the Ferret]

if it's like the one n my FZ it is for emissions and gives more torque at lower rpms

[The Spaceman_imp]

It's a valve that opens and closes depending on throttle opening. The idea is to increase back-pressure at lesser throttle settings and decrease it at higher settings. Generally speaking, it'll give you better performance at both settings. And by happy coincidence it keeps the bike quieter when you're putting along, and gives you more sound when you whack the throttle.

Yamaha calls it EXUP, and Suzuki has just added it to the new VStrom 1000 ABS; they call it "SET" which stands for "Suzuki Exhaust Tuning." The CB 1100 does not have the feature.

[Deanohh_imp]

I think in some markets it has one.

[The Spaceman_imp]

I think in some markets it has one.

I'd be quite surprised, but I don't know for sure one way or the other. I do know the bike would have to have a completely different FI and exhaust setup to accommodate it.

[Randy B]

Here is a pic of it.

[wildezt_imp]

its that flippy flappy thing that opens and closes controlling the exhaust aperture..to alter the velocity of the exhaust emissions and back pressure...is what i heard.

[Tyke57nz_imp]

I think in some markets it has one.

My machine has this fitted, a while back I took the end cover off the silencer to investigate and it is operated by cable from a servo positioned by the collector box. Not sure what will happen if an aftermarket silencer were fitted, guess you leave the servo operational without the cable. Might check with Staintune on that, as one of their silencers is on my wish list. Can take pictures if required.

[the Ferret]

I think in some markets it has one.

My machine has this fitted, a while back I took the end cover off the silencer to investigate and it is operated by cable from a servo positioned by the collector box. Not sure what will happen if an aftermarket silencer were fitted, guess you leave the servo operational without the cable. Might check with Staintune on that, as one of their silencers is on my wish list. Can take pictures if required.

Not required but pics would be appreciated so we can all see where it is and what it looks like on the CB. I don't see anything in the pic Randy posted.