Turbos are very quiet - turbocharger is directly in the exhaust path. I used to run my tuned Evo on the road without a muffler and it was only slightly beyond tasteful - don't try that with a GT3 - ever hear an RSR at the track?
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73 Carrera RS 2.7 Carbon Fiber replica (1,890 lbs). Former: 73 911S, Two 951S's, 996 C2, 993 C2, 98 Ferrari 550 Maranello