Originally Posted by Jordo!

That's seems... unlikely... even with open headers the factory intakes should flow more than enough air.

Did you have a tune? My guess is that fueling and or spark just wasn't optimized for the headers.

Anyway, I was a bit suprirsed at first to find little or no evidence of huge differences between a modified factory intake set-up and cone filters, which are theoretically much more flow friendly, but the difference does indeed seem to be fairly minimal.

The factory airboxes just aren't particularly restrictive (no wacky butterly valves in the way, and already has ducting to the bumper to bring in cooler air), and the plastic pieces do a good job of blocking underhood heat too. Nissan did a good job -- go figure.

Basically, the smoother tubes and less restrictive element flow about as well as the cone filters. The possibly (but unconfirmed to the best of my knowedge) cooler temps that might be achieved with the G3 or a similar CAI design, which may (or may not) have a better location to draw air than the factory ductwork are proably somewhat negated by the fact that metal tubing will also conduct more heat than plastic and silicone.

So, actually, the relatively small addditional gain over modded factory isn't really that surprising if you really think about it...

That said, if you are a serious power junkie and desperately want every last whp , if you can find the G3's for ~$200-$250 used, I think it would be worth it as you spend almost that much on high flow panel filters and tubes, so for a little more cash you get a few more hp.

Brand new, IMO, the price is kinda steep for what you gain in power over the modified factory set-up -- I guess if you really like the sound, one could argue that's another bonus to justify the price...

Oh, on that note, there is some evidence that cone filters that do not draw air from in front of the bumper (i.e., "short rams") appear to lose power over the factory boxes, a least on the basis of a few dynos...

So, cliff notes...

Bang for the buck = high flow filters + silicone smooth tubing.

Money no object, gimmie every last whp -- I live life a 1/4 mile at a time = some sort of CAI (i.e., "long tube") set up.