Hi DClocal. The MACH system also has no droan. The Street Race system isn't all that loud. The agressive tone that it has really never gets out of hand. However if you put the free flow cat with either the Race or Street Race kit it becomes loud. The free flow cat and the Mach system sounds about 10 percent quieter than the Race version with the stock cat. From what you were saying I would probably suggest the Street Race with stock cat, or the Mach with free flow cat. Our free flow cat has yet to be tested long term. We need to test it to see if it's free flow nature trips the engine light etc. Flanges (laser cut stainless) should be ready in about 10 - 15 days. Then we can get Shabby's car back and start the testing. Thanks.