Control valve on the exaust pipe

[Jun]

Does anyone know what does the control valve on the exhaust pipe do?
When you look through the rear grill above the exhaust pipe you see the valve.

[harrison]

It quiets the sound down at low revs for sure, and may add beneficial backpressure for more torque. The extra torque numbers , I don't know. The stock exhaust sound is at a weak-sauce level for sure. You really must review some prior posts. Actually read them all before taking delivery. IMO

[Jun]

You are right, additionally I just had my R8 serviced, so I asked the technician he said the control valves on both sides will open during high rev to balance the high exhaust gas flow, and of cause the sound will be different during high rev. Thanks...

[harrison]

Mr. Jun, My neighbor, here in So. Cal. has recently packed it up and moved to Bangkok, Thailand !!!!! Obviously, you live in a beautiful country. If I get invited to BangKok, Thailand someday , I'll look you up , O.K ? Take care.

[London Lad]

You are right, additionally I just had my R8 serviced, so I asked the technician he said the control valves on both sides will open during high rev to balance the high exhaust gas flow, and of cause the sound will be different during high rev. Thanks...

Not quite right

The system has four tail pipes coming from two different areas of the silencer box, two each side.

In order for the car to pass low speed drive by db tests one pipe on each side is blocked off by the two valves you can see.

The two valves (one each side) open at about 4200 rpm. At lower rpms the car is artificially 'muted'

[desperado]

Jun,
There is a lot of information in this thread:
Disconnect exhaust valve, so always open?

[London Lad]

How could I have forgotten that thread :-)

[willyjp]

The valves are also open during cold engine start-up....thus the throaty startup sound compared to the sound with warm restart.

Does anyone know: is 4000-4200 rpm the ONLY criterion that opens the aux. exhaust valve (with a warm engine)?

Sometimes, I get the feeling (hearing!) that they're opening below 4000 with strong throttle-opening movements.

[Jun]

Mr. Harrison you are most welcome, I'm sure you will love Thailand especially the Thai food.
Mr. Desperado, thanks for the thread about the exhaust pipe