Need a muffler for Lime Rock?

Guys,

I'm doing Lime Rock for the first time in an new car (Ford 1600cc). I've heard LRP is very strict on noise levels. Do any of you guys run there and if yes, do you need mufflers?



If you do run a muffler, I'd be interested in what it is (well, how much attenuation you needed).



Thanks



John Feng