Wonder how many HP one could gain?
Maybe the biggest exhaust pipe ever seen (http://www.youtube.com/watch?v=T7rOPVwbNi8#normal)
Only when your driveway and streets are made of hand laid bricks are you rich enough to afford a nice nonrestrictive exhaust system such as that one...
I can only dream of owning such a system one day.
I can remember when megaphone exhausts on four stroke race bikes were considered normal practice!
AND BLOODY LOUD TOO!!!!!