The air intake tube on my XKR has a couple of strange looking protrusions, what are they?

After market metal tubes don't have these, does it matter?

 

They are pressure wave dampers, they also reduce the intake noise. An expensive refinement that the manufacturers of replacement parts deem not needed.

Good explanation here https://itstillruns.com/air-intake-r...-12156112.html

 

Kevh,

In general, if something is on the car it’s there for a reason. Jag did a lot of R&D in the design of the car. These bits cost extra, and so aftermarket mods generally do away with them, esp. if they cost more to manufacture. Lots of aftermarket parts are available but some do away with the purpose of the original OEM component. In the case of air intake dampeners, these are dead air spaces that reduce the air shock on rebound. Makes air travel smoother through the tunnel.

Had a Porsche which had a K&N “cold air” intake cone in place of the air box. Trouble is the cone sat in the engine bay so it wasn’t drawing in cold air. Original air box had tunnel to outside the car via a Louvre trunk slot. So aftermarket mod did exactly the opposite of what was intended at the factory.

 

To my knowledge, these are made to capture the compression waves/sounds coming from the supercharger blades and traveling up the intake. Jaguar must have made some tests and determined that the loss of intake pressure was too big to pass up at some rpm/frequency and that well placed resonators would help by either fattening or even elevating the torque curve.

 

I thought the idea of them was more to muffle the supercharger noise then increase performance. I'm interested in installing an early NA smooth tube to see if it makes a diff in supercharger whine, which I want.

 

I just replaced the old intake with one from Mina Gallery along with a K&N hi-flow filter in the original air box. It screams like banshee now, lots of supercharger noise.

 

tagged

 

Many NA engines also have these. They are (Helmotz) resonators that mostly effect the sound by dampening the natural resonance-frequency of the intake tube. They can also help a small amount when you suddenly opens or closes the throttle by reducing negative or positive shock waves. This problem however are often been taken care of by the electronic throttle body on "newer" cars with drive by wire accelerators.

 

can you post a pic of it?