Ok, I've been searching for this the past 3 days and came up that the 06 stock intake tube has better velocity. But, visually only by pics, the tubes from the non-revup and rev-up seem to look the same. How can you tell the difference between the 2.
(I have an 06 but sold the stock tube, I want to buy another one. I just don't want to be fooled by someone saying it is the revup when it's not)

Thanks

 

velocity stacks

 

sorry i'm a newbie...what does that look like?

 

Something like this:

 

03-05 intakes: small metal ring (after the filter, before the intake tube) that smoothes out the flow

06+ intakes: same thing, except as mentioned, it has a velocity stack (similar to what gothchick posted) which accelerates air coming into your intake tube.

HP difference: who the hell knows

 

just get whatever one and add a turbonator.

 

My altima had one. My 06 had one untill i cut it off with a hacksaw and made my own shortram intake. No idea if it made more HP but it looks and sounds good.

 

thanks everyone....so the velocity stack is actually in the filter housing and not the actual tube...air filter housing > maf > tube > tb

 

I just bought a 2006, 6spd...yahooooooooo! This car is baddassss!!!
Although I felt the engine was restricted, either the air filter or exhaust... but the stock muffler seems to sound/flow pretty good. So after reading the web, the word is to keep the stock airbox. It is actually designed pretty well, a radiused snorkel type inlet that smacks right into flat panel filter, then a pretty straight tube to manifold. Only thing I would add is an inlet extension to the grill. So I added the K&N panel filter ($40) and Shazaaaam!! What a difference... Immediate throttle response, no lag, quicker rev up, and carries through entire RPM range.... the stock box gets pressurized from RAM AIR, so I highlu doubt any CIA will flow better with all that turbulence and misdirected hot air from engine..... Hope that helps y'all....

 

strange, i looked inside my 06 z-tube and see nothing that even looks like a velocity stack. its just a straight tube from end to end.

 

Yeah I think the only velocity stack (sometimes also called a Venturi stack I think...?) is the contoured ring mounted in the airbox between the filter and the MAF sensor housing. The tube is just hollow I do believe.