There isn't any "officially" documented flash for FX. Basically, there isn't that many people that does the flash and it's not really offered as a package like it does for other cars like Porches, 350Zs etc.. The best documentation will be here, especially on Technosquare since there are plenty of members in CA lucky enough to drive there and get the flash.
Now on the other side, our engine is basically the same engine as 03-05 350Z and 03-06 G35 coupe. If you search my350z.com or g35driver.com, you'll see the offerings and what will be the average gains. That same gain (not the end hp) should apply to the FX, if you are RWD. If you're AWD, you're in bad luck since there aren't any AWD 350Z or G35 you can compare the results with.
That said, no dyno is the same and each gain will differ by the tune. Since each tune is done custom, not as a single simple package, the results may vary significantly. Sounded like a cancer drug ad.. :.smile: