I'm curious to know, from some I've heard that the smaller stock plenum is better for FI because it holds pressure (don't even know what that refer's to, simply holding boost?) better than the larger aftermarket plenums. Then on the opposite side, there are dyno's floating around with the gains made by those aftermarket plenums. I'm a little lost on which is "better", but I've installed a crawford anyways. I see alot of the FI 350z guys keeping the stock plenums, so it's kind of bothering me now. Does anyone want to enlighten me?