Since this thread has become the all-things-custom-headers-thread I'm posting here.......
I was in on the first batch of custom headers and after install it was immediately clear that the bike would benefit from a dyno tune. Surge at small, constant throttle openings, a general lack of crisp response to inputs, etc. This wasn't a surprise, I was actually pleased - the motor needing more fuel because its moving more air is a good thing
Here's my experience -
I wanted to try the Rapid Bike system based on my web research but ultimately went with a Power Commander. Not my decision really, any reputable shop within a reasonable distance was far more experienced with the PC. One was willing to try the RB but my bike would have been patient #1.
My header has 3 O2 ports, one for each pair of cylinders and one downstream of the merge. Unfortunately, the header pairs the left & right cylinders (iow a front and rear). The technician highly preferred front-front & rear-rear cylinders for tuning purposes. As he said, the temp difference between front and rear cylinders is large enough to make a difference. We ended up using the single O2 port past the merge to tune
We didn't go for ultimate power but rather smooth throttle response. Even so everyone wants to see the numbers so Max HP = 106.0 Max T = 55.2. Dynoplot down below
Mods are WiLD headers, flow balanced injectors, Pipercross air filter, Micron exhaust cans
Results - throttle response is much, much better now. Crisp, linear, no surging, no stumbling - puts a smile on my face each time I open it up. Sadly riding season is almost over around here š
Dyno Plot VFR800.pdf