Reader Question: Adjustable Exhaust?

Here’s the latest reader question, along with my reply!

T asks: A couple of decades ago I did some work for a guy in Fashionable Ferndale. (In case you are familiar with him.) I had to sign a non disclosure agreement so I can’t give out details. But at one point in his career he worked at the tank plant in Warren. It was rumored that the Abrams tank used a series of microphones and speakers in the exhaust system to cancel the exhaust noise. Today, noise canceling headphones are in common use. I have three different kinds. For hunting, at the range, and the ever popular Bose for rocking out. And while Bose is using their system to eliminate road noise in high end cars (and of course EVs), I had a short conversation with a guy in a new car who told me he can adjust the sounds of his exhaust. This seems like a future fatwa in the making. What kind of repair costs will be associated with this type of exhaust? How many “sensors” (microphones) are involved? What does a heat resistant speaker cost? Does this system eliminate a conventional muffler? For some reason I picture a trip to the parts store and paying five grand for a catalytic converter.

My reply: Several new cars have what is styled “active” exhaust – which basically means there’s an actuator/baffle that can alter backpressure and so pitch/loudness. Usually, the exhaust note gets more aggressive when Sport mode is dialed up. Some cars (BMWs) also have electronic sound enhancers – but to my knowledge – these are not driver-adjustable.

The “active” exhaust does have moving parts – and electronics – that will inevitably wear and tear out and require service, probably costly.

I’d rather have the old-style mechanical cut-outs … or better yet, a catalytic converter “test pipe.”

Remember them?

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