Anybody done the youtube DelBoy's cutting off the end of stock mufflers, pulling the cat out and then repacking the muffler? Guess it's lighter and from vid has great sound.

 

Watched the video...some time ago. Chose not to take that route.

Have removed and re-fitted baffles many times, many bikes. Not rocket science.

Times change...and so do tastes. In my youth the cops would write a bike-ticket pretty much any time they could - often the excuse was their claim that the "baffles were removed" - there's a vehicle code statute on this in cali. I do not see cops doing this much anymore...and I have some pretty loud bikes. Since the bike scene has moved away from the blue-collar class toward less impoverished people maybe the cops' lack of enthusiasm is a recognition of class privilege...maybe.

The narrow power-band associated with straight pipes can be mitigated by careful attention to design - using acoustical design rules - and it can be done by amateurs - but the physics does not believe in tears, or hope, or anything except reality. If you do not get it right all you have is noisy scrap metal.

Pretty much the pipe id has to change at the right places and a reflector disk will probably be needed... Fuel, cam, all this and more, matter...a lot.

Simple method - buy engineered pipes and accept the sound they make.

Drilling, removing disk (which is about ,060" thick mild steel, surprisingly thin) allows the supersonic pressure wave (as differentiated from the slug of subsonic gas that is pushed into the pipe by the exhausting piston) to exit the system. In the OE design this supersonic wave is reflected back toward the open valve by that disc...

Removing the disk, the "baffle", puts that supersonic crack into the environment where it cannot add to engine output (as designed) and it instead bangs away on your ears.

There's plenty of power, so the probable power reduction isn't a big deal. Adding snuffers may be worthwhile...but then you're almost back to near stock. Snuffer disk reflects that wave back up the pipe....and can be tuned, unlike stock design. Variable snuffers are louder than leaving things alone...

Depends on what you do for fun...

 

Here are a couple videos of a much better & easier solution to get good sound AND good power out of modified stock exhaust.

These modified stock slip-ons dyno out better than any aftermarket slip-on.



Video for slip-ons with cats



TTI LINK