i havent gotten any responese when i posed this question in other intake related threads so i guess ill have to make my own. please take a moment to really inspect the airbox/ducts esp while the hood is closed before responding as the answer may seem obvious at a glance when the hood is opened.

can someone take a look at the oem ram air intake piece thats above the radiator thats supposed to be sucking air into the airbox? when i look at it i jus dont see how air is sufficiently getting sucked into the airbox. the hood pretty much closes access to it,and it sits above the radiator way above the grill. watever air is being pushed upwards from the grill is being bounce off the fiberglass reinforcement thing so the air flow cant possibly be that smooth..plus the top center part of the grill is actually blocked off and u have all the hood latches there which is where the air duct thing is located so even more so air aint being directed in to the duct.

...plus the opening on the duct is so narrow its like trying to drink from a narrow "L" shaped straw. so idk... then theres the mysterious "power duct" thats obviously there to take in air (otherwise it wouldve been sealed off) yet the hood appears to be almost blocking it off so im sure air is not easily being flowed there esp with the little gap the hood leaves when its closed.

before i get flamed im sure nissan did its R&d or else they wouldnt have designed it that way but i jus have a hard time understanding how sufficient the air flow into the airbox is.

thanks

 

I see what you're talking about. I think the air ducts are positioned more for cool air. The engine will suck the air in and that's where the cool air is when the car is moving.

 

The hood does not seal off either inlets. There is about 1" to 1.5" gap forward of the inlet to let air when the hood is closed. The air source is the grille area which is pretty much ambient air at speed.

A little bit of info most don't know is that the Power Duct is not used on the 1st gen G25's overseas. The duct is actually just a cover and the only air source is the over radiator inlet.

 

^in that case air from the engine bay is getting into the power duct opening then? also must be difficult for the engine to suck in air from the narrow angled duct above the radiator

 

Don't forget about the 1.5" tube under the airbox that takes in air from below.

 

^ wat do u mean?

 

I noticed this and posted about almost 2 years ago...hood when closed appears to be shielding all intake ports
I drilled 12- 3/8" holes in metal support which is in front of air box...then pushed marker through these holes to mark air box...then drilling corresponding holes in air box...the difference in performance was........NONE

 

^u tried to do wat the z guys do with their bumpers?

 

The smaller the diameter of a given object, the faster/higher pressure a fluid will move through it; like putting your thumb on the tip of a garden hose.

The "power duct" may be small, but in order to effectively channel air a a speed that would produce a power adding pressure, it must be small.

In fact even with that small of an opening the power (1-3hp ~Nissan) does not come into play until roughly 60mph.

With a naturally aspirated engine we aren't looking at that important of an intake, and really the only beneficial bolt on mod besides a spacer (and lower plenum for RevUP) would be a bigger throttle body.

 

^but the engine is sucking air in not pushing air out per ur analogy

 

The intake (at 60+mph) effectively becomes a semi ram air system. But yes, the vacuum created by the intake valves opening/pistons moving downward is sucking air in at all times.

Edit: When the throttle plate is open.

 

^so at those speeds the air thats bashing against the radiator through the grill is probably going upwards and somehow getting into the narrow openings on the duct above the radiator? id imagine now much air is getting into their

 

Air is getting in and it's nearly ambient temp air once rolling. Verified with the datalogger. Even at a stop, the intake typically sucks in air about 10 to 15 degrees over ambient. That's far better than the 40 to 70 degree+ air over ambient that is sucked in by most aftermarket intakes.

 

May not be the ideal, but I don't really see why people go crazy over intakes and the likes... With our n/a cars, sure it may make you feel better knowing it is getting more, colder air but I have yet to see any intakes or modded intake systems produce any type of significant power increases.

 

i doubt any will ever provide any SIGNIFICANT power gains, but its about the big picture... when you dont have much money you do things 1 at a time, so over time, that intake will help. with more bolt ons you will see more power and that intake will play its role in the overall power gain.