I have a 2010 XK Portfolio. I love the V8 sound I get from her but would like a bit more of a burble at times. Does anyone know of a company that does upgrades with some kind of on/off switch? Thanks in advance. Martin
What you are asking for is practically what Jaguar used on the XKR but theirs is an extremely complicated way of achieving it. The naturally aspirated cars have much simpler flow related valves on the silencer to alter the run of exhaust gases through it. If you are prepared to mess around on a trial and error basis, you could always try wedging the spring loaded flow valves anywhere between partially and fully open to achieve more of the V8 woofle. It wouldn't be quite as quiet for cruising as standard but you might be able to find an acceptable compromise for very little cost. Mike.
2014 XK Dynamic R convertible; 1977 Daimler Double Six Coupe; XE S