Quote:
Originally Posted by benzy89
IIRC, Shiv or Terry commented how Valvetronic has gotten in the way with making adjustments to run higher HP. If the turbine was really the only thing getting in the way, why did they make the single-turbo upgrade for a car that came with a TT?
If you really want, I'll find the comment that mentions Valvetronic being the problem. Another difference between the motors: N54 comes with forged internals. N55, not so much 
That's how come you can see FBIS putting down 650+ RWHP and the engine hasn't been cracked open to put in new cams, piston, rods, etc etc etc |
How about we just stop regurgitating forum nonsense, and only post if we have first hand knowledge. Nobody has yet to verify whether N54 *OR* N55 are forged or not, and/or which individual parts are forged. It's purely speculation.
The larger valves and cam duration is a fact. It's documented in the technical information on the N55.
As far as Valvetronic interference goes, when you are WOT, the valvetronic system holds the valves all the way open. There really isn't anything to hold power back then (no different than N54). If you're somehow measuring N55 power delivered at partial throttle loads vs. the N54 (and have it documented as being greater somehow), I'd be glad to see it.