Are these pipes a copy of standard, or are the specifications for each model calculated by a tuner or tuning software?
Different models are built to different specs. based on design, space, experiance and feedback.
The side pipes as mentioned above are a compromise pipe, as are all sidepipes.
There just isn't the room to build the size and length needed when attached to the side of the bike
My CZ side pipes have headers that are a very close copy of the originals and are interchangeable with originals.
The chambers are a slightly different spec and don't have the huge dents in them that the originals have and this helps them perform better than the originals. Also come with built in mufflers.
360 at front, 250 at rear
360 header
Heatshields are a laser cut copy of the original 360 heatshield
The post 70 models are completely different to stock.
They are a one piece design with built in muffler, I get good feedback for these models.