Exhaust Cut Off Valve

Hi guys,

I want to introduce an exhaust cut off valve that is in some way controlled by throttle. I have a lovely loud exhaust but don't want it quite so loud unless I'm WOT. Could I simply buy a second throttle control valve and splice in to the one on the inlet manifold so they both activate together? Or could I use some kind of vacuum valve connected to the vacuum system?

Ideas please :)

Thanks in advance

Edit: I have all the intake mods, K&N panel filter and the fpr running off the inlet manifold btw. Also have a sports cat and middle box removed from exhaust with twin exit ovals on the back. Just in case any of that makes a difference to answers lol