Power Valve

[Panzer Patrol]

This things been bugging me, so I had to find out the story, and here it is from the BMW press release:

" A further special feature is the pressure-controlled valve integrated in the muffler which controls exhaust gas counter-pressure for an additional reduction of noise under the engine's primary running conditions at medium to low engine speeds. This keeps engine noise at a lower level, but at the same time allows the rider to hear that famous flat-twin rumble that everyone appreciates so much."

I dont know what they are on about when they say "keeps the engine noise at a lower level" What I do know is, on my 1150 the diameter of the pipes in a Y piece has a noticable effect on the engines torque. If they are too large in diameter, the motor will rev more freely but it loses a some of its bottom end grunt. Smaller diameter pipes retain the engines torque, maybe even increases it a bit, but it doesnt seem to want rev as freely. It might be wishfull thinking on my part, but using a valve in the silencer to maintain back-pressure for bottom end, but also allowing more flow at high rpm, would seem like a good idea.... just a thought

 

[ianm00]

My GS1200 is an 05 bike with black exhaust end BUT NO valve thingy!

Ian

 

[Rich]

My GS1200 is an 05 bike with black exhaust end BUT NO valve thingy!

Ian

TBH I havent seen one without a black end. Mines an 05 (based soley on the fact it has a small toolkit) and I have the 'thingy'.

 

[John Armstrong]

05 reg plate in Hawes this weekend, silver end piece and no valve. I can't see it being kept on ice for six odd months prior to it being registered, can you?

 

[Wraithwrider]

This pressure operated valve was in the press blurb when the 12 was released.

So talk of 05 bikes only is just talk.

I think that someones pulling someone elses leg here.

I also think that they've all got em, just that some can't find it.

Mines in the attic, with the original headers.

 

[Mikef]

I did some on board videoing the other day and had a remote mic that I taped to the framerail near the endo of the exhaust where the valve thingo is (I wanted to get the blokey throaty roar of the 1200 on tape rolleyes: )

On the playback you can hear the thing "wittering" away on the overrun a bit but not quite like the noise from one of those turbo pop off bling bling cars (technical description)

Sounds cool

 

[John Armstrong]

I also think that they've all got em, just that some can't find it.

Got to disagree as I know what I'm looking for, and the bike in Hawes didn't have one. However the ehaust's might have been modified in some other way to get the same effect.

 

[swebb]

I picked mine up today, and had the dealer confirm with the frame number that it's definately off the 05 production line.....

and guess what... mine DOES NOT have the "valve" thing...

and yes, i do know what i'm looking for...

guess that blows the 05 theory out the water then.... hmmmm

 

[Deleted account 211025001]

I picked mine up today, and had the dealer confirm with the frame number that it's definately off the 05 production line.....

and guess what... mine DOES NOT have the "valve" thing...

and yes, i do know what i'm looking for...

guess that blows the 05 theory out the water then.... hmmmm

Mine's an 05 picked up on March 1st and does have it.......mmmmm

Maybe BMW have been using up old stock of 04 cans hence the current inconsistencey in relation to model year??

Still, all academic really 'cos once a power comander bcomes available a nice 'open' system is going to go on

Andres

 

[Wraithwrider]

Got to disagree as I know what I'm looking for, and the bike in Hawes didn't have one

Fair comment John.

It'd be very interesting to get the dirt on what's going on here.

 

[Eddy802]

So, is the valve set up a good thing or not?

Can we assume that it's fitted to exhaust systems that are in other ways different and therefor it contributes to the overall system and menas with or without, you get the same power delivery etc?

 

[Rich]

I picked mine up today, and had the dealer confirm with the frame number that it's definately off the 05 production line.....

and guess what... mine DOES NOT have the "valve" thing...

and yes, i do know what i'm looking for...

guess that blows the 05 theory out the water then.... hmmmm

My theory is that there's 05s and 05s. My 05 was in the showroom waiting for me to buy it, and therefore is probably in reality a Sept/Oct 04, which BM consider an 05. This is when the first 05's are born, Im told.
Perhaps the valveless 05's were born in the Jan production cycle. So the valveless ones are v v new.

Wonder what else is different....don't say youve got a full toolkit

 

[Jockser]

Checked mine last nite (the power valve ! )

March 05 bike with steel end plate on can & no power valve (at least none externally )

Also have the crappy toolkit.

Bike feels the same as the 04 demonstrator I had my test ride on but as they're both yellow maybe that explains the stunning turn of speed !!

 

[STU12]

Just had mine serviced. 4 others parked up outside, black end covers had the valve , silver ones didn't. Oddly all the silver end cans were on wire wheels.

So , obviously , if you're on wire wheels and have a silver end can without a 'valve' thing, you've got the slow version.

HTH

Stu

 

[GrinningGSer]

Delivery Feb 05, small toolkit no puncture repair kit and I do not know how to tell if it IS an 05 bike ? Does anyone know how to tell production date fron chassis no?

Black end to exhaust and HAS valve thingy !

Called into local dealer today and two R1200GS's in showroom:
Yellow with silver end has NO thingy
Yellow with black end HAS thingy

Presume both are 05 bikes

I asked the mechanic and he was completely unaware of what this thingy was and also unaware of any change

 

[Chisurz]

Is this where someone needs to put one of those 'Poll' panels up with all the different options to see which do and which don't???

Just to add to the current 'body of knowledge', mine is definitely a Feb '05 build, does have a silver 'zorst end, does have wire wheels, does not have the strange thingy (and is quite fast enough thank you).

Conversely, a yellow 'off-the-peg' model in the dealer, has been there for a while, has a black 'zorst end, alloy wheels, and does have the strange thingy... This dealer bike is almost certainly built prior to Feb '05.

So work that one out.

Meanwhile, those of us lacking the strange thingy can relax in the knowledge that with these highly complex machines there is one less thing to go wrong...

Still doesn't tell me definitively what it is and what it does though... Very low on my GAS index...

 

[Rich]

Ive decided it was time to go international on this. Insomniacs may like to monitor this thread:

http://www.advrider.com/forums/showthread.php?p=1349569#post1349569


I'm getting pretty certain its a later build 05 variant.......its evolved!

 

[bezzer]

I picked mine up on 9th march apparently it was on the production line at the end of feb it has a sliver end and no thingy.

I WANT A THINGY!!!!!

 

[swebb]

Just to be clear...

Mine ordered months ago, picked up 23/March... dealer confirms it's 05 production line.

I have silver end on zorst, and NO THINGY...

and have the added (dis) pleasure of the useless toolkit too...

but downright dying to know what the damn thing is, and why it's on some, not others, is it a good thing? bad thing? indifferent?

oh the questions......

 

[Wraithwrider]

Could this be yet another cust cotting exercise?