2010 RT Exhaust Valve?

[Riverdawg]

The motor controlled exhaust valve on my RT seems to open wide around 5000 rpm and the sound and power "seem" to rise. Has anyone investigated (tinkered) with opening this valve all the time and if so with what results?

[BMWLou]

The local BMW shop told me it was there on order for BMW to pass the noise testing mandated by EPA. Not sure if I believe this or not but I would also like to know the "real" reason for the flapper valve and if it can be elimiated.

 

Lou

[Limecreek]

Noise is the reason for the flapper valve and removal will throw a code.

 

Is there a reason you want to pull it?

[BMWLou]

I have a Remus Exhaust System left over from my 05 RT. Was thinking about installing it on the 10RT and the exhaust flapper would not fit.

[NewBlue]

It's there for noise? and here I thought it was for lower RPM tuning. Oh well live and learn

[Paul Mihalka]

Noise may be the reason, but not to make it quieter (old stock is quiet enough) but to get a bit more "thump" when on the road and still pass EPA etc. It is also possible that a tight exhaust helps low rpm torque and a more open exhaust helps top end power.

[dirtrider]

Afternoon Robert

 

Right from various BMWNA advertising hype.

 

*The new valve control in the exhaust system ensures a discreet but more dynamic sound.

 

*Electronically controlled exhaust flap for superior and powerful sound.

 

*Electronically controlled exhaust flap for superior and muscular sound.

 

No mention of any engine power or torque improvement. If it did help power or torque BMW would surely mention that fact as an added improvement. They don’t miss much when it comes to advertising hype.

 

From the little effort I have put into looking at that exhaust sphincter valve operation it operates opposed to what you would think it would for low RPM power/torque improvement but does seem to position itself for a low/mid RPM throaty sound then throttle that sound at EU-3 sound test RPM/road loads.

 

Maybe BMW has plans to use that valve like an EXUP valve in the future but so far it doesn’t look that way at the moment.

 

If you want to play with it you can disconnect the valve cable from the servo motor going to the flapper valve and wire it open without it setting any codes as long as the wire harness going to the servo motor if left hooked up.

 

[Ken H.]

Right from various BMWNA advertising hype.

 

...more dynamic sound.

 

... for superior and powerful sound.

 

...for superior and muscular sound.

 

No mention of any engine power or torque improvement.

Indeed. The value is there to make the bike louder under certain conditions, not to make it quieter.

 

I’ve mentioned before how disappointed I am that BMW caved to social (or should I say anti-social) pressures on this. BMW joining the, 'part of the problem not part of the solution' crowd. Sigh...

 

[NewBlue]

I'm amazed by this. they have an ECU controlled exhaust flap and they use it for noise and not tuning. They should give Yamaha a call. Just shaking my head and shrugging my shoulders!!!!

 

Happy Thanksgiving All