Coming from a two-stroke background with some insight into the pressure waves and reflections in expansion pipes work, but with next to no knowledge of how 4-stroke exhaust tuning works - I never really understood how the free-flowing pipes or cherry bombs were supposed to improve power.
Is it reasonable to assume that if the pipes have simply been opened out like mine, even with the fuelling adjusted, all you're ever likely to get is a lot more noise, but either little to zero gain (or in fact a slight loss) in true torque and power at most points across the rev-range ?
Alan, I need to pick your 2-stroke Brain... 2-stroke folks absolutely Understand Reversion!!!
Reversion is Important in a 4-stroke also.. You will Understand when I say that High Speede Gases travel the center, and low speed gass, the edge... I can prove that simply Eliminating (reversion trap) reversiopn helped My Dragbike, and others who gave it a real try... Also explains why, the Crossover Pipe Works (certainly Street applications),
I believe that even straight thru Mufflers, with a Baffle outside edge, Takes some "bite" out of Both "rash noise", and some bit of Reversion. lends Manners when applied to Drag Pipes, Certainly..
Anyway... we will get together when we both gots some Time...
Later my Friend...look forward to Learning some of that 2-stroke Magic!!!!