Hi guys!
I've recently bought a Bentley Flying Spur 2007. It's my first Bentley and I love it. Mine is not Speed version so it seems that it doesn't have on off pipe, so it's a little noisy inside the cabin all the time. Friend of mine has 2 BFS Speed version, and on normal D mode, the pipe is deadly silent and you can hear the "brum brum" sound in the cabin only at Sport mode.
So, it there a way to lower the pipe sound ? Because I drive daily so I prefer a quiet car. But to be honest, on Sport mode, the sound is fantastic.
Many thanks

 

Nice car! Does yours have an aftermarket exhaust? If not it should be very quiet....

 

Thanks It's original pipe came with the car, or maybe there is something else making it not quiet?

 

Are the exhaust valves / dampeners connected at both the left and right mufflers ?


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Thanks a lot! I'll check this right away

 

I check and both are connected, and from the pipes I can see it open when the engine is off, and close at warm iddle. The pipe is very loud, there is no different between sport mode and normal mode 😭

 

Is this exhaust note switching option also on the GT? I'm guessing not.

 

I think this option is standard for GT and Speed version. My friend's car Speed version is very silent on normal mode, but sounds loud on sport mode.

 

Something is wrong with this picture, the flap is open, there should only be one flap for each side of the vehicle, not 4 flaps in total if that is in-fact what you are saying by "one is open and one is closed", one is a straight pipe and the other is flapped, the flap should be closed at warm idle, opens under hard acceleration or sport mode.
Was the engine running at the time of picture taking ?


Johnny


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Your picture that I marked with the green star, is not closed, that pipe is a baffled piece, what is shown in your picture is the other end of that pipe, as in the other end of the muffler.

 

Hi Johnny,
Thanks for your help. You are right, the photo was taken when the engine is off. I will take photo when the engine is on warm idle and post here tomorrow.

My friend car, Speed version is very silent at normal mode, do you think it has different pipe system?

 

No, we need to see that the flaps are physically closing when they should .
So let's wait for your next picture.

 

OK, then how is it activated?

 

Vacuum .
They are spring loaded open Vac closes them .
All quad pipe high end set up the outside pair of the quad is vacuum valved . It’s a generic exhaust system not Bentley specific .
Ferrari , Maserati , Aston , Alfa , M series BMW , Merc AMG etc etc .Bentleys quad are disguised by the oval tail pipe trim .
To permanently keep the outer pair open + associated noise if you wish , you pull off the Vac pipe and block it off .....self taper or golf T .This fools the engine management and no CEL s .

So when you initially start when cold , it’s open hence the growl until there’s sufficient Vac to pull it shut .

Sport mode or hard acceleration cuts the Vac .....it springs open = the noise .

 

How ever having said what I said in post #14 the pics look odd as there appears a valve in each pipe .
Inner is open , outer closed , which is normal if the engine is off .

So for the “ sport “ / loud sound to seemingly be there all the time there must be a fault that opens the outer ( and the inner in this case ) all the time .


So no vacuum or insufficient vacuum is eaching the outer valve to suck it close and it’s prematurely opening = loud noise .......This needs investigating.