I prefer my K&N, as (I think) it makes a better noise, plus the K&N comes with a cold air feed. I was thinking of making up a bracket for it, but it's fairly snug in there, and I've put bubble wrap between it and the top of the inner wing, so it shoulodn't rattle.
I thought the whole secondaries system was to give different valve timing at low and high revs to promote smooth running? Also does this not mean that your engine will be running massively rich at low revs? I'm not a mechanic by any stretch of the imagination, but I would imagine this can't be doing your engine a lot of good, plus you must be spending a mortgage on fuel!
No, the fuellings taken care of by the ECU, so the engine fuels to whatever volume of air is entering it. O.k. it's never going to rival a diesel for economy, but that's not why I bought the car. As for the valve timing, the Duratec doesn't have variable valve timing, so it makes no difference. Ford fitted an IMRC for fuel economy, and low down torque(possibly emissions as well), my car pulls cleanly(if not as briskly) from below 1000rpm in fifth. Anyway the figures speak for themselves, 0-60 in 6.72 secs.