jus put my harley stock drilled out pipes on temporarily while modifyin my triumph of rd pipes fitted a k'n n filter removed the bottom of filter an drilled bottom of airbox an gor blimey govner ive got the sound!! so no qualms about guttin the triumph 'noisy' pipes now! cos i know the sound wont be far of!!an it goes a lot better with the k'n filter[with temp harley pipes]no noticable low end loss of torque in fact it seems to pull better at low revs[19t'42t] with a lovely deep rumble an a bit o thump!!i was tinglin with pleusure at the sound!![no annoyin burble like a lambretta on steroids!!]while blastin past queues of cars with seemingly less effort!! i will post some vids of the sound soon as i fix a camera to me bike!!