We dyno-tested three different exhaust systems mounted to a Suzuki DRZ 400E:
1) Suzuki stock, 2) Yoshimura RS-3, and 3) QuietStorm. In addition to making a whopping 10 dBA* less sound, QuietStorm matched the horsepower gain of the aftermarket pipe at 9000 rpm. Just as quiet as the stock pipe, QuietStorm pumped out 10% horsepower gain over stock at 4000 rpm.
* Every 3 dBA reduction represents
half the sound.
Using a dynamometer, we tested a Borla muffler installed on a 1998 5.7L Camaro SS. Then we replaced only the muffler with QuietStorm. Not only did it reduce sound by an overall 4 dBA*, it gained up to 8 horsepower over this popular aftermarket muffler.
* Every 3 dBA reduction represents
half the sound.