Well, I finally think I got the Ram Air as close to perfect as possible with stock air box.... [The most recent touch was the additional foils to direct more air into the dual intakes.]

Anyone got ideas how I can improve it more? Anyone know if I can somehow get a bigger air box and still get my MAF sensor to fit?


Heres the pix-









If you want to get more details on the setup for ideas on how to improve the story is on my cardomain site p.6 (here: )

http://www.cardomain.com/memberpage/362498/6

 

i thought ur gonna spray paint it

 

does those things scrape? It looks lower than my previous Stillen lip.

I would definitely paint it black so it doesn't stand out so much.

Eric

 

It might work well, but thats ghetto.
Im sure it scraps.

 

I definately take care so as not to scrape em!

You think I should paint all of it black? Im kind of fond of the silver in the front - im about to paint the non-metallic parts black. Thoughts?

 

Paint it black so it shows less.

 

thats quite fugly. but it works, i have a similar (tho much less apparent) setup.

 

MY 2 pennies on this talk..

Its hard for air to force upward to ur intake from that BC it has to GO up the Tubes to the Air intake.
If it was on more on an angle & IF you Removed the 1 Foglight to make the Bend a 45deg angle It would work well on the Highway.. (ive tried this, it worked well but the construction wasnt there..)

You tryin to Make 2 90deg turns with that air.. 1 to catch the air and once inside the pipes it has to make another 90deg turn to get in that Stock airbox.. Not the best way to go...

alternatives: #1 Quick release on ur 1 headlight and get real good response/power. #2 Get some Flexible Gutter Spouts from Home depot and remove the Fog light .. Make a FORCED air kit with that Flex-crap and mount it w/ rivits on the edges..

 

Here ya go-

 

OK, a couple points that I have considered in my design:

1) air doesnt mind going UP as if gravity slows it down (negligible factor). Was this a point you were implying? Kinda sounded like it.
2) 90 degree turns are indeed a real problem for induction when the diameter of the tubing is realatively small compared to volume of the air passing through it. At 4 inches in diameter at the smallest point I have done much to aleviate the hindrance that the required 90 degree turns impart to the positive air pressure.
3) The flexible gutter tubing is alot smaller and thus less condusive to an optimal setup (per #2)
4) the gutter tubing has big ruffles that add big time constriction and turbulence to the airflow, especially at high velocity.
5) I dont want to have to mess with the headlight and I want the setup to be "always on"

PS it looks alot better live so those of you comin with Fugly should know that it looks quite good in my opinion, and even if it didnt I am of the perspective of "function over form" anyways. Peace-

 

prorbuly adds power but not my .02 , it sticks out to much

are you running a stock air box stil??

 

Its not that noticable. I had to get a worms-eye view to take those pix. Most of the time you can hardly even see it... Probably the most common way is if it rushes up in your rear view mirror and even then its gone PDQ

Im using the stock air box because I got so much air coming in I dont have room for, nor could I find a hi-flow air filter that can manage with the setup.

I decided to maximize positive air pressure into the K+N filter / stock box rather than take less positive pressure and a larger surface area for filtration. Seemed like the best way to me.

Maybe Ill go looking for a truck air box in a junkyard that the MAF can fit onto. Sounds like a longshot...

 

Can u feel a difference in power? If so, where at? My friend's Grand Am GT has ram air, and at highway speeds, it really does somethin for him.

 

It makes the mid to top of 3rd pretty daym skippy. 4th also seems more like 3rd and a half

 

If you have trouble falling asleep tonight read this, it should do the trick: Dispelling the Myth about "Ram Air" in Automobiles

 

Like said before, this won't work. The air won't actually go into the pipes, it will go under and around them.

 

At the risk of starting an argument, I must suggest that your statement is incorrect.

You suggest that the air is actually going to AVOID the intakes?

Oh, and that article was inaccurate in its conclusion section, I will re-read the whole thing soon and let you know what I think but from what I saw it had a wrong premise.

Heres another article on the subject that had some measurements:

http://www.sportrider.com/tech/146_9508_ram/

 

Looks like the front end is unbalanced grasshopper.

 

Even more when I sit in the car

 

OK, I have read that article and it makes good points. The main disconnect that I would say is happening is this: Ram-air setups can make gains in other ways than actually compressing the air being funneled. Ram-Air generates high velocity air, resulting in some net positive intake pressure (even though it does not appreciably increase the air density)
This positive pressure can work to benefit engine performance by counterracting /offsetting the inherent negative pressure present in all intake systems. Negative pressure that occurrs because of:

1) Filtration/ forcing the air through the air filter
2) General friction from the sides of the channel/tubing along the way to combustion
3) Turbulence caused by friction and impediments.

So it seems to me that Ram-Air can provide gains w/o achieving what the author states is the only way to achieve gains on his web page e.g.: Air does not have to be compressed (or have its static pressure increased) in order to help the maxima engine to burn fuel and create more power. I agree that much larger gains would be demonstrated by compressing the air per turbos or SCs... but our engine can benefit from having a greater volume of air transported into the cylinders to burn more fuel -if a condition exists where air is an appreciably limiting agent.
For the VQDE it seems to me that this is the case with a stock intake at most RPMs, and also for hi-flow intakes at high RPMs, since the USIM is not designed to deliver air in that range with the addition of the resonance effect that occurs in the mid-RPM range.

If im wrong then why would the power die off in the higher RPM range? It would have to be something besides a lack of air to use to burn fuel, and the only thing that would account for that would be the fuel injectors inability to deliver fuel amounts rapidly enough at engine speeds >5000 RPM which seems like nonsense. So its gotta be that the engine is not getting enough air and anything that increases the amount of air that gets into the combustion chamber the better.


Please correct me if Im wrong but this stands to reason to me. I admit I could be wrong of course... but... I do feel more zip!


Oh and another thing occured to me:
Quote from the article:

The amount of air which is inducted into a cylinder is a function of the air’s density. As the air flows through the intake tract, it loses pressure, and as the pressure decreases, so does the air’s density. (Denisty is mass divided by volume. Since cylinders are a fixed volume, increasing the density will also increase the mass of the air in the cylinder.) There are two ways to increase the pressure and density of the air inducted into the cylinders:

- Decrease the pressure drop from the throttle plate to the cylinders

- Increase the starting pressure at the throttle plate.

Ram air is an attempt to do the second. Under normal circumstances, the air at the throttle plate is at atmospheric pressure, and this pressure drops until the air reaches the cylinders. Ram air would start the process at some pressure higher than atmospheric, and even though the drop is the same, the cylinder pressure is higher because of the increase at the start.

I think the author has misrepresented the case in this quote.

I can see a way that Ram-air can also alleviate the first bullet point, and that it does not only try to address the 2nd as that dude (whoever he is) wrote.

Why in bullet point #1 above does the pressure drop from the throttle plate to the cylinders? Seems to me because the engine is [*Edit] ATTEMPTING TO [/EDIT] draw air molecules at a rate faster than the intake pathway can provide. If you increase the speed at which air molecules can be provided then you lessen the pressure drop. Its not necessarily about increasing the air density to provide less change in pressure, its about reducing the situation that creates the need for the pressure to change.

Thoughts? Rebuttals?

 

now i like

 

I commend your effort to find ways of adding more hp....but damn that thing looks ghetto.

 

Might be the ugly duckling to some- but its poetry in motion to me!

And it might just get me a 13.99 N/A... on street tires...

It look gud dammit!

 

That looks like some junk got stuck to the bottom of your car. Blast, too bad dynos wouldn't show the real life gains.

LEMAR

 

Sure, I got some rebuttals.
"Ram-Air generates high velocity air, resulting in some net positive intake pressure"

It doesn't increase intake pressure. The number of oxygen molecules remains static, regardless of speed. There will not be any more air put into the cylinders to burn. Without compression, the volume will remain the same. Ever stick your head out of a car window when you were a kid? It's not easier to breathe with the wind blowing in your face. It's actually harder. The air is bouncing around, and objects in motion tend to stay in motion. More force is required to change the direction of the air molecules. And when you inhale, you don't force the air into your lungs. You reduce pressure in your lungs by expanding them, since pressure is a function of volume and space. The atmospheric pressure attempts to equalize, forcing air in. With molecules moving at velocity, the energy exerted by that pressure is less effective when some of it has to be wasted changing the direction of the molecules. The air doesn't avoid the pipes, like Big D said, but the molecules bounce around inside of them when it reaches the limit of what the intake system can contain at that specific pressure.


"If im wrong then why would the power die off in the higher RPM range? It would have to be something besides a lack of air to use to burn fuel, and the only thing that would account for that would be the fuel injectors inability to deliver fuel amounts rapidly enough at engine speeds >5000 RPM which seems like nonsense. So its gotta be that the engine is not getting enough air and anything that increases the amount of air that gets into the combustion chamber the better."


Our engine dies off at high RPM because of lack of air, that's right, but it's because of the design of the intake manifold. Guys with intakes still have the drop off at 5500 rpm. The intake system is only as free flowing as it's most restrictive point, so even the best intake will be restricted at the manifold. Ram air will have no effect of this. Even with a hypothetically perfect intake manifold, the amount of air available to burn would be restricted by the volume of the cylinders. A ram air will have no effect on this.

Essentially, because the ram air creates no pressurization, the psi is still whatever the outside atmospheric pressure is, there will be no increase in the amount of air to the cylinders. Even though the air is moving faster, there will be no increase. In laymans terms,

10 million air molecules = 10 million air molecules.

10 million air molecules moving at 60 mph, still = 10 million air molecules.

 

I guess I was trying to impart this idea- And I could be wrong- but it was interesting to me. Never mind the fact that I said net positive pressure- thats too sketchy an idea as it could mean actually compressed air (which I didnt) or air acting from a pressure (the velocity of the car's forward motion- which I did)

Since the net pressure drops as the combustion chamber increases in size (creates a net vaccum that the air molecules mush accelerate towards to fill)
one of the (possible?) reasons that the power dies off at the higher RPMs is that there isnt enough time in the 1/2000 of a minute (figuring 6 cyclinders @ 6000 rpm and 1/2 the cyclinder travel time allowable for air entry) for all the air possible to enter the combustion chamber that could (and thus resulting in 1 ATM of pressure in the chamber before compression and combustion)

So this net depressurization of the air in the combustion chamber and the generation of less power might be caused by the fact that the air isnt travelling as fast towards the combustion chamber as it needs to be or could be. Maybe the force of the wind when the car's speed is above 70 MPH helps to lessen the generation of this depressurization at high RPMs. Not by Pressurizing the air but by making it more accessible FASTER in order to prevent the generation of the pressure drop in the cylinder. The pressure drop in the cylinder that is a result of the enlarging of the combustion chamber faster than the intake can provide air to fill the vaccum that is generated.

I gotta run to the beach so I cant really re-read this... I hope it makes sense.

Cheers

 

I think you should try to mold something that looks neater and will look a bit better.

 

Cool air beats hot air every time. But unless you have a restriction between the throttle blade and the atmosphere (air box, flex) I don't think your going to see any benefit other than cool air. But cool air is an accomplishment and nice work too BTW.
On most cars there actually is a spot where you can pick up some atmosphere+, the center of the hood, and bottom of the windshield. If you could stick a manometer tube right there you should see some slight static pressure increase. But it is also very turbulent air; see post above about sticking your head out the car window.

 

I see what you're saying, but I think as the air has to be drawn through the filter and around the many bends and twists of the intake manifold, the air will not be moving at 70 mph anymore anyways. It only maintains that speed until it reaches the filter, where it is slowed down/ bounces around, and only what the filter is capable of passing will pass through. The air won't move into the cylinders any faster unless it is pressurized, with with a turbo or supercharger. Seems to me that ram air is a lot like that $30 electric supercharger thing, you know, with a fan that blows into the intake? It might even slow the car down, with the reduction in aerodynamic efficency. But it'd also allow the intake of cooler air. Might be a trade off, but it's all speculation.

 

Yea... its really frustrating not being able to test its effectiveness...

Maybe a couple 1/4 runs with the air box open and the filter taped to the top- cold air would be coming in close to the filter so it wouldnt be much (hopefully) warmer and it wouldnt be a "closed circuit" kinda thing and thus not accelerating the air or giving it that 1% additional pressurization that I am secretly hoping for.

If there was a consistent and notable difference in top speed in the 1/4 well... then there might be something to go on...

Let me say again yall... Sounding defensive I know

It looks good to me, and Im really mostly concerned with performance!!!!

EDIT: AND you cant even really see it unless you sit on the ground!!! DEFENSIVE DEFENSIVE DEFENSIVE I know!!

 

credit where it's due for trying something new, but after reading that article on vetteguru.com and hearing eric/bluemaxx's arguments, I'm not really sure I can agree with you about it helping performance any.

as far as looks are concerned, its not so bad. if I saw that on another maxima on the street, I'd be tempted to stop him and ask what it was. it looks... "interesting". not ugly.

 

Thanks for not dissing me at least!

Im a bit cranky right now cause I just hurt my shoulder at the gym so pardon me....
I think ram air works, and I can notice marginally better pull at high to extreme speeds. I think people who dont believe ram air does anything at all might be (in my opinion are) taking a narrow view.
-Note that I referenced an article that has lends evidence to the case that ram air works. The only debatable question in my mind is this: Is the setup that I have running creating enough pressure (NOT COMPRESSION) to make any difference? I think it does but always would like to find a way to make it better if possible.

As with everything else, people would rather keep believing what they already are inclined to believe, myself included

If I get better 1/4 times and speed with the setup as opposed to open air box then I might bring this topic up again. But Im thinking it doesnt seem like I am going to hear many suggestions on how to make this work better...

 

It might move faster than w/o any ram air effect, and it will not slow down (much) over the course of its passage. If it did that would mean that it is pressurizing or compressing. What It may be doing though, is making the overall speed for a molecule to traverse from the intake to the combustion chamber faster. Any additional speed increase would be a bonus and its not like ONLY a turbo or ONLY a supercharger actually makes a difference. Just a bigger more noticeable difference...

To try to illustrate: Yes, the filter will limit the velocity of the air molecules, but not to an absolute speed that is characteristic of the filter per se... air molecules velocity through a filter with no ram air effect will quite probably be alot less than the air velocity through a filter that is connected w/o any breaks to 2 large gaping intakes that are being pushed forward at highway speed. Doesnt this stand to reason? You get PRESSURE pushing air through the filters and along.. Not necessarily COMPRESSION of the air.

Air moving faster through the intake and toward the combustion chamber REDUCES the amount of net or resultant DEPRESSURIZATION that invariably happens as the piston moves and creates a vaccum for air to fill for detonation of fuel.

 

I could whip out my physics books at argue about this, but there's a lot of variables, and I'm not going to claim anyone is right or wrong. If you feel a gain, then it's good enough. It's only an intake, people need to calm down about the subject.

Anyway, the one point that I will make is that some (if not all) 97-99 (and maybe 95/96?) maximas have a stock ram air tube. Everyone knows it does nothing because it is tiny and not exposed to much air. Obviously nissan thought it would do SOMETHING (perhaps if it was designed better), and that something was increase pressure, period. The documentation says that it is connected to a boost sensor - it's been so long, but I dont remember any specific sensor, but it's clear what they intended. Positive pressure, not positive velocity. But then again, the design sucked, so take their intentions how you will..

 

Sweet. Sounds like more evidence supporting that there is some potential.

And I do have that little boost sensor in my engine bay only its not connected to the old stock intake anymore

 

If nothing else, it blows cold air on the filter element. It probably can't create positive static pressure but it sure as hell can reduce the vacuum. I think the thing we're missing here is that it's not all about positive pressure. Also, any knowledgable turbo guy will tell you it's not about PSI it's about CFM.

 

A water manometer is easy enough to make from clear tubing. You can use it to measure presure drop or increase. I'd say if it moves at all, no matter how much, you can prove or disprove your theory.
BTW, I was/am in no way dissin' your efforts. They laughed at the Wright brothers too, and you know how that turned out.

 

I didn't think anybody was getting excited over it. It's just an intake. Spaniard asked for rebuttals and thoughts, so I gave mine. No offence buddy, if you thought I was insulting you. if you like it, good for you. That's all that matters anyways, if you're happy with your new intake, nobody else's opinion matters. It's your intake, you're using it, not theirs. I got more rebuttal, but I've got a research paper due tomorrow, and I've been procrastinating. So it'll have to wait.

 

Its all good- Nothing wrong with the discussion IMO... Maybe I got a little defensive so my bad. I feel more educated from it so thanks are more in order than anything else

One thing that occurred to me- if there is a way to get a reading off of that boost sensor (im not an electronics person but I imagine there might be a way to wire it to some electical thingie) then perhaps that is the best test possible... Just look at the readout at different speeds (like 70,80,90...)

Im heading out to take a closer look at that doo-hiky

 

That was a decent read. I don't know jack about fluid dynamics, so I can't verify what it says, but it sounds good enough to me.

I think one thing this "ram-air" intake can provide is constant access to fresh cold air. That alone should be motivation for building such a thing.