http://www.ft86club.com/forums/showthread.php?t=57369 lol

Nice exchange on info and perspectives everyone, thank you! It seems to bear out what I've heard that the OEM exhaust manifold is deficient from a performance perspective mainly due to the less than optimum merging of the exhaust gases before they're routed into the cat, hence the torque dip that gets reduced/eliminated once a header with a better collector is in place.

For my purposes, I'll likely eventually end up with one of the CARB certified centrifugal superchargers and will be swapping back in the OEM manifold/cat every 2nd year. That may also mean I'll need to reflash between two different tunes once ever 730 days if I want to fully maximize the non-CARB setup (or not if there isn't enough difference to warrant the cost of a 2nd tune). The good news is that here new vehicles no longer require a smog inspection/certification until they reach six years old.

The advanced multiplier also wasn't set to 1, hence a fresh ECU reset for the pull. Don't let that chart fool you. There isn't a single header that eliminates the dip by itself on a stock tune. Someone even made the dip look like it went away on a stock header because of ECU resets.

Which is why i'm still waiting for independent dyno charts for both the OFH and FT86SF header before I commit to buying.

Do you happen to have a link to that post? How would an ECU reset make the dip look like it went away?

I'd like to see the background behind this, too.

Currently running the FA20club catted EL header, awaiting the replacement pipe from FA20club to make it cat free. It is a reasonably priced header with good gains, I wonder if the primary cat removal will be a noticeable change.

OFT Stage 2 EL Header Gas Tune 1.55b runs very well with this header.