Car Engine Noise Control

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When new vehicles come with engine noise control, are they making engines quieter or louder? Is sports car engine rumble a lie, or are they blocking out some of that noise?

In: Technology

It probably has what’s called a valvetronic exhaust which when engaged, closes partially thus muting the overall sound. When the valve is opened, more sound comes out. This is extremely simplified, however fairly accurate. Race cars generally don’t have any mufflers as they restrict airflow and if you are tuning a high performance engine, you want the least amount of airflow restriction possible. A free flowing exhaust allows more air to exit at once, thus allowing more air to enter at once. Does that make sense?

A lot of the “feel” of a powerful engine is because the engine is directly mounted to the chassis/frame of the vehicle. Some of this can be negated by placing buffers between the engine and the frame, so that the amount of vibration transferred to the frame is decreased. You can also have noise dampening material placed between the engine and the cabin of the car to decrease the amount of noise.

In higher end luxury cars, you have more of these dampening features because they also decrease the amount of road sounds in addition to the engine sounds. The size of the frame will determine how much of this dampening can exist. This is why even though the Cadillac CTS-V (third gen) and Corvette Z06 both use [6.2L LT4 supercharged V8](https://en.wikipedia.org/wiki/LS_based_GM_small-block_engine#LT4), they sound and feel completely differently.

You can put resonators in the exhaust along with the catalytic converters and muffler to make it quieter, your exhaust is also not mounted directly to the vehicle but on hangers that are connected to rubber mounts.
Also newer car engines are encased in plastic with rubber engine mounts.
Mats inside the door and under the vehicle help with noises from the roads and to help deaden sounds.