Over the winter, I set my exhaust guy a challenge. Develop a solution where I can quieten the exhaust with a flick of a switch.

I love the sound of my Cerbera, it sounds like all TVRs should, but there are times it would be nice to be able to dial it back a bit temporarily (early morning departures etc)

I knew there would be a number of challenges, the main 2 being:

• Is there enough space to make a box big enough to have the desired effect
• Can I use vacuum to open/close the valves

• In the above gallery, the first image is the valve we used. It is a default-open valve and vacuum fed
• The 2nd image is of the box fitted in place, with the valves shown by the yellow arrow
• The 3rd image is the view from the rear

So did it work?

The short answer is no. What did work was the valves closed as planned fed with vacuum from the inlet manifold. This was important, as the alternative was to use electric motors, and those are both expensive and would take up more valuable space.

The Achilles’ heel though, is the amount of space you have to work with at the back. The available space is restricted in height due to the fuel tank, and by width. By the time you allow for the ins and the outs of the pipework + the valves on each end- the resulting volume you have you can use for silencing clearly isn’t sufficient. I didn’t even bother measuring the DB’s, it was clearly not good enough.

I’m not giving up though. There is a plan B.

We do these experiments so you don’t have to 😉