The Stage 1 pipes have a long cone shaped baffle in them with multiple perforations through the wall of the cone so no where near as restrictive as the standard pipes but rather noisier. G56 pipes are more classically straight through with perforations into the absorption part of the silencer. They are fairly big and bulky in order to get the noise down to a decent level. The original sports pipes from MMC were really quite loud though allegations of passing Spitfire pilots not being able to hear their engines over the racket were slightly exaggerated, but only slightly.
