2008 R8 V8


Yesterday we installed a HMS performance exhaust on a R8 V8. Fits stock "flap system"
Startup and idle to about 2k rpm the car sounds perfect.

But now here is the problem.
Between 2k rpm till 4,5k rpm the car becomes dead silent, can barely hear the car when driving.

What is that??

And after 4,5k rpm the car opens fully and gets crazy loud.


Looking forward to get this problem Solved.