There are a lot of posts over on another board (Titantalk) about the JBA headers. They are not well received. Since no one here has supplied that info in any detail, I would suggest a search over there before buying.
No one, I repeat, no one who is posting their dyno sheets and drag strip print outs there has anything good to say about those shorty headers.
Generally speaking, they have found our header design to be as good as aftermarket shorties. Rather, the big gains are coming from unrestricted cat-back systems coupled with Volant intake and using a dual in muffler or an aftermarket Y pipe to eliminate a big restriction and choke down in the factory y-pipe. There are some reported gains also in removing the second cat (or knocking out its honeycomb) which is after the O2 sensors in the 4x4 models.
But shorties don't seem to help. Everyone, me included, is anxiously awaiting long tube headers being promised from NISMO and a couple other aftermarket sources, and an independently verifiable programmer or tuner chip.
