I had both the Dbilas item and VF Engineering one on my car (very similar to the EVOMS: apprarently the EVOMs is supposed to be louder). ANyway the VF item you could here loads of sucking noises in the car and a metallic fluting noise when lifting off. With the Dbilas all you get is an induction noise barely a little louder than standard, the same performance and no sucking noises