CC:
When you do exhaust headers on any relatively high performance engine, you don't just do the muffler shop bend dance. You need a bender that maintains a constant diameter throughout the entire radii of the bend. If you don't use a constant radius bender, the actual diameter of the pipe as far as gas flow will be the smallest inside diameter and that will occur in the tightest radii. Consequently, your choice of benders is severely limited. To fabricate a high performance header and do it right, you need DOM (Drawn over mandrel tubing) with a relatively low Rockwell and stable chemistry and access to a good quality inserted mandrel bender like a Baliegh plus a good working knowledge of geometry and thermal dynamics and you'll still put a lot of prototypes in the scrap bin. Just message Travelguy on this forum or on .com. He's knows all about the header game.
The stock 'header' on the R3 isn't a header at all. It's a tubular, thin wall medium quality stainless manifold much like the cast one on your car except this one is on a bike and it's not cast because of aesthetics but it might as well be. There is about zilch in efficiency concerning exhaust gas scavenging with three cylinders feeding a like diameter trunk pipe feeding a mass of plumbing underneath terminating in three mufflers with more baffles inside than there are Arabs in Dearborn.
My take on all this is simply that if I wanted to gain additional horsepower and torque as well as a more pleasing sound (I don't, I like the motorboat sound), I would get a set of Jardines or Staintunes or some other aftermarket setup where you actually get a set of (engineered headers). Whomever made them did the dirty work and the engineering and you pay for that but believe me, it don't come cheap. To give you some idea about equipment, a Baliegh Mandrel bender with a limited set of mandrels and forming rolls with basic Numerical Controls will set you back around 150K and you still have to have the knowledge to run the machine and produce correct parts.
It gives a great amount of personal satisfaction to engineer a product such as an exhaust system but you have to be prepared for a large amount of disappointment and frustration before you attain a workable result.
If I told you how many of the Flipmeister clamps went in the scrap bin as I sorted out different problems with them you'd probably not believe me. From concept to reality to a viable product at a competitive price while still making any profit at all is a fine art.