Getting More Exhaust Sound
The loudest overall setting is in Sport+ when the idle speed goes up to 900 and the electric valves on the rear tailpipes open up a bit more. However, there are still variances in the amount of sound at different rpms, indicating the valves are actively moving to different degrees. There are two passages in the mufflers, one more restrictive than the other. The valves divert the exhaust partially to the more restrictive passages to reduce the sound level. The valves are not fully open to the less restrictive passage except under heavy acceleration when there is maximum sound. I noticed that actuation of the valves is not by vacuum as with most other cars, but by electric solenoids residing on the top of the tailpipes just in front of the rear mufflers. So I tried disconnecting the switches above the solenoids to see if that might just keep the valves open all the time. Effectively, open valves would let all the exhaust go through the less restrictive passages in the mufflers at any rpm. Success. Now it sounds like a NASCAR racer from idle. Your neighbors will know you have a V8. The switches are snap on. If you want to try this, be careful separating them from the solenoid bodies by unlatching the plastic tabs on the tops. Cover the exposed electric connections on the switches and tailpipe solenoids with electric tape so that they will stay clean from road grime. It seems that the factory first designed the mufflers for straight through operation and maximum sound. Then they probably decided that they needed to reduce the sound at varying rpms to keep most customers happy driving around town. Thus there are two passages within the mufflers. BMW and Jaguar do this too, as do probably every manufacturer that has an "active exhaust" option. I bought it for the V8 sound and am happy with the unrestricted sound all the time. When it is time to trade it in, just snap the switches back on, and it all goes back to normal.