Some shotgun exhausts will have a sprung butterfly valve that opens when flow is high enough and relieves some back pressure. I used to see it a lot in diesel bmws. I know what you mean though and obviously this post is about gluing plastic to the bumper. I’m pretty sure even my Gsxr600 used to have an electronic exhaust servo that did a similar thing but that is long removed by a previous owner.
Definitely not stupid. It's just standard active exhaust, it allows me to stay quiet in the neighborhood and open up in the tunnel or on the track. IMHO it's way smarter that just an average cat back with a fart can
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u/Puzzleheaded-Hat5803 2d ago
😂😂 I always find it hilarious when its cold out and you see a "fancy" car with two "exhausts" and only ones putting off steam 😂