vq35de vs. vq35de rev up...

Sorry If this question sounds ridiculous, but I've looked everywhere and can't seem to find the answer. My question is what causes the torque on the rev up vq35de (05-06 350z) to be lower than the regular vq35de(03-04 z)? Any help will be appreciated. Thanks guys in advance.

higher compression, different intake design, and a slightly different variable valve timing system. and some ECU tuning also.
and direct injection too.