Would you want to make a standard exhaust quieter? I have the Librands Sports exhaust system fitted to my 4/4 Sport. I've been running their Sports Silencer for a couple of months and have just fitted the 4 branch manifold and sports cat to the car today. It was quite boomy at certain revs with just the sports silencer and if the manifold increases the noise I'll probably try their Acoustic Trim. Rob Wells at Librands told me it makes no difference to the power output but thats with their full system.
