[Signmaster]

Originally Posted by cujoe_da_man

So, are we talking about inside or outside the car that you can hear it?

You would hear it under certain conditions inside the car as well as out.

The flow of air through the intake is interrupted when the column of air hits the closed intake valves. This creates a pressure wave that bounces back into the intake system, fighting the incoming air. This is taking place for each cylinder, so you have multiple pressure waves trying to bounce back, while at the same time intake runners are seeking incoming air.

Most resonators simply allow an expansion chamber area to allow the pulses to be dampened and slow the pressure waves coming out. Done properly a resonator will actually aid intake flow under certain conditions as well as reduce noise.


Intake sounds with short runner intakes and individual carbs/throttle bodies and filters can actually be fairly loud and pronounced. Similar to a car with a bad misfire trying to accelerate... that thump, thump, thump, thump....

That is because the air column has very little restriction, and virtually no dampening when the pressure wave is created. It simple expands as it exits the air filter.