Sound enhancement tube delete

  1. My model of MX-5 is: __2011 Sport Tech
  2. I’m based near: __Newcastle

After fitting some new suspension to the car and refitting refitting the parts i’d removed I had a good look at the sound tube thingy. I’ve always thought there was a weird noise which I didn’t like and presume this is partly responsible, So…I’ve removed the part that joins the resonator to the bulkhead,. It was a little tricky as there are two hard plastic tabs holding it together.

I’ve ordered the blanking plug for the hole in the bulkhead.

As you’ll see from the pictures the tube from the inlet manifold doesn’t vent into the cabin as many thnk, the resonator part is a sealed diaphragm that vibrates and therefor passes sound through the bulkhead. A bit like a speaker but instead of being driven by an electrical voice coil it’s movement is made by the intake pressure. If this wasn’t a sealed tube you’d have unmetered air getting into the engine.

Mine now simply makes its noise into the engine bay. I can’t see this being a problem.

Hope this is helpful.

I disconnected mine as well all I did was put a plastic cap on the wall and on the pipe left every thing fitted …

I may well do that when the blank arrives.

I looked at the one in my ND, but other than being a bit of weight that seems unjustified, I have not noticed specifically the noise it causes, so will leave it.

I have ordered some sound deadening matting for the boot floor - so will try that over Easter whilst off and see if it makes a difference.

Normally I have the hood down, so it probably does not make a difference, but as I took my son to work this morning early, he did not want to “mess his hair up”, so I had the hood up on the way there and down on the way back. I noticed that it was quite loud, so thought I would try some sound deadening. There was a thread on here elsewhere, so I have ordered some of that. Will report back (with pictures!!) when I find out what the result is…

Oh I’ve already done quire a bit in terms of sound deadening,… The purists will no doubt hate my added weight in the boot and the doors but it’s much better with than without.

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Where did you get the blanking plug from, please? Is there a Mazda part number?
Looks like you have a gap now - did you plug the end of the resonator tube too?