Jardine headers look near stock, but flow better
I have used them on my bike for 220hp/187ftlb N/A in 2009, & 350hp/300ftlb F/A in 2010
Have ditched the Jars now as they were holding back the other mods, so making a lot more now.
As others here will confirm better breathing, more in more out should give you close to what you'r looking for.
More than that costs $,
Don't worry about numbers, just play a bit at a time, start with opening up exhaust after the header, let your butt tell you if it's fast enough.
Some people end up with more power than they can actually use anyway, me included.
Opening up the pipe after the header, and getting a better breathing intake can get you some gains. The stock header will restrict the power above 5000 rpms, but the low end torque is still what most people are looking for.
Here's what the Boost is good (a.k.a. Turbo Connection) kit with a Dynojet PC5 can get you:
211 rwhp and 225ft/lbs torque
This is a variable vane turbo so there is no lag. My boost gauge goes instantly to 10 PSI when I crack the throttle any more than about 20%. I like the fact that when I'm not in boost it's basically a stock motor... runs smooth as silk. In boost... all hell breaks loose.
And I've called them twice with questions. Each time I had to leave a message but they called me back both times.
I will probably be wanting boost someday, but this winter will just be small changes that give modest power gains. it only has 3000 mi on it so far. just trying to learn all I can. Thanks to all for your knowledge and sharing.