Air Intake - What is this Box?

[burrellbloke]

Does anyone know what this black plastic box is?



@EthanMenace has been working on removing bits from the Clio to fit the V6 airbox and when the battery was out we both noticed that the air feed that starts as a hard plastic tube at the left side of the grille and then goes in to the standard airbox/induction kit on the right also has a tube that goes in to black plastic box under the header tank.

Does anyone know what the black plastic box is and what it does?

 

[PITA]

It’s a resonator box to reduce noise

 

[burrellbloke]

Thanks Craig.

 

[Dave W]

To just put a bit more meat on the bones and (apologies if it gets boring - 30 years in automotive and powertrain engineering does this to you - sorry) to explain further.
Those resonators are put there for a couple of reasons. Most popular is not so much the reduction in volume but to tune the sound waves of the intake system to be more favourable to the driver. They work by offering a volume of quieter airflow akin to blowing over the neck of a bottle. Also of course they are useful in reducing drive by noise effects in certifying vehicles.

Then we go and throw away probably 0.5 million Euros of work by Renault and replace with with a blaring foam filter, giving us back some of the unpalatable sound waves. And yes, guilty as charged

 

[burrellbloke]

Thanks for information. I have got no doubt that Renault would not have put something in the engine bay if they did not think that it “added” something to their design.

I have removed the resonator now as a V6 airbox is going in. I will have to put up with the airwaves and noise, and hopefully more torque.