I had noticed on another forum where someone with a current model XK8 swapped out the rear portion of his exhaust system and installed the quad pipes from a current model XKR. He had noted that there was a vacuum actuated valve on the outside pipes of the XKR exhaust. Is this also the case with our vintage (2003-2006)?

Doug

 

Disregard the dumb question. I looked underneath and noticed the quads are dummy trim.

Doug

 

the 07 and up XKR Doug is not a dummy pipe for the Quad. It opens the outer pipe when vacuum drops with is full throttle accel and startup. Dramatically increasing the agressiveness of the exhaust note. I have a normally aspirated rear muffler next to the garage from an 08

 

This is the same system Chevy uses on the new Corvettes and VW uses on the R32's.. I think it's a pretty cool idea, but everyone that buys a car with this system tries to disable it to make it permanently loud anyways, so it's kinda pointless..