At low RPMs, #Akrapovic exhaust system for the #Porsche 911 Turbo S emits a deep flat-six rumble, moving through a powerful mid-range, which then develops into a rich and high-frequency acoustic sensation at high revs. Such race-inspired exhilaration! _ _ _ _ Emission notice: http://emission.akrapovic.com This Slip-On Race Line (Titanium) with Evolution Header Set (Titanium) does not meet emission compliance requirements for street or highway use.