I did a search on past strings and it has been a while since this topic has been brought up (as far as I could find). I wanted to see if any one has any new info.

I want to create a funel from the the opening ware the fog lite goes. From there a tube that conects to the stock air box. I would like to cover the opening with the stock honeycomb grill.

Has anyone done anything like this, any sugestions or better yet any pics?

 

A good intake is a good intake. . . but just so you know, ram air is a misleading name. You cannot stuff air into a hole, unless you are traveling faster than the speed of sound. . . read a physics book. . . it's true.

What happens when you blow air into a bottle of water? The air goes AROUND the bottle. You cannot compress air by simply having an opening at the front of the car. However, the front of the car is a great location for taking in fresh, cold air.

Ram Air works because they are good intake designs. . . designed by engineers for optimal flow. Designing your own intake (ram air or not) is pretty much futile. . . unless you are only questing for more sound and noise; you will never match the output of a well designed aftermarket intake, assuming you don't have a degree in engineering or something.

 

I'll tell you what I did (a science experiment if you will):

I tested the 'ram air' idea by taking out the Foglight cover. My Injen filter is right behind the foglight opening. I took it for a spin and felt little to no difference. These engines in N/A tune will have no need for such an opening due to their low intake limits/needs. If it were FI, it would make a world of a difference. Hope that helps.

 

I agree with what you are saying in reguards to the bottle of water, However I beleive that 80 mph winds will increase presure to the intake. Infact I did a simular setup on my accord a I noticed a 5 mpg increase.

I know that at low speeds it will not make any diffrance other that the cooler air, which for every degree cooler on a n/a moter will increase hp by 1% (So I have read).

 

cool idea

 

What you are talking about is compressing air by travelling at high speed. . . and to this date, the only vehicles on EARTH capable of doing this feat is a ram-jet/scramble-jet aircraft. You must travel beyond the speed of sound to even begin compression in the first place. Read any text, ask any professor, compressing air with wind speed alone is IMPOSSIBLE, barring resonance, which happens only for a split second.

Your previous experience and resulting performance gain was because you were drawing in fresher air, probably with less bends in the pipe. The reason "ram-air" works is because they are a good intake design with almost no bends in the pipe.

Unless you develop a high tech intake, with mandrel bends, high grade high flow materials, and minimal bends, all developed accounting for resonance, optimal air vortexes, etc. . . you WILL NEVER EVER EVER match the performance gain of a good aftermarket intake. EVER. Don't let the butt dyno fool you.

NOw if you are talking about venting an aftermarket intake with additional cold air, you may see some gains.

Just remember that well designed aftermarket intakes already yield small gains, relative to other cars. An improperly designed intake will usually do more harm than good, not acheiving optimal flow. It will probably sound better than stock, but I can gaurantee that you will not get more than a 5hp gain. You have a VERY SLIM possibilty of gaining 1-2hp. . . and more than likely you will lose some power.

 

What we are actually looking for is an increase of air pressure at the intake, which would in turn make the engine work less to "pull" in the same amount of air. That would equal less wasted HP, and use that saved HP for turning the wheels. Which is what we all want. The possible problem with this system, is that during times of no car movement, you will actually be wasting a little energy to "pull" the air through a longer tube into the factory filter box. As stated before, you will gain the cold air, which will help in HP. CAI"s have a longer tube, but a less restrictive filter, and supposedly a very smooth interior wall, which helps with any HP gains. Hope this helps.

 

wow this is great timing...

I just did this very thing this weekend. I took the foglight cover off of the driver side to expose my Injen short ram air filter. then I inserted my custom made screen into the foglight hole. and admired my Sunday afternoon work.
I didn't drive the box until this morning. after getting up to approx. 50 mph, and then slowing down at a light, the engine quit and the check engine light came on. this happen once while driving toward work and again when I turned around to go back home to insert the foglight cover.
five minutes later when I started driving back to work - no problem; box runs fine.
conclusion: I didn't notice a thing when I was driving it w/o the foglight cover. also, I guess I should note that it was the first time I drove it w/ the freshly cleaned/oiled filter.
anyone want to chime in on opinions, comments, hints?

 

According to aerodynamics, you cannot increase the pressure of the air. You can move air and displace it, but that doesn't increase pressure. However, you will reduce pressure at the rear of the vehicle. Lift/Drag/Aerodynamics work via low pressure zones. . . again, to significantly change the pressure of the air, you need to either change your altitude, travel faster than sound, change your altitude, or change your temperature.

There have been plenty of articles on this kind of thing. . . Just do a little bit of research. . .

here's one simple simple post I got from a quick google search. . . there are tons more

http://www.celicatech.com/forums/showthread.php?t=106

 

I think I will just do it and see what the results are. I think that instead of going to the stock box I will just create one using the injen short ram trim the arm so I can put an inline cone filter and a 120 degree angel cut and smooshed to fit in the opening.

I dont care if it does not give me hp gains but atleast it will be a custom intake that not everyone has.

 

check out my pics. i have the injen short ram which comes out behind the drivers foglight. does this help? i dont care. custom dont come in a box, it is a box

 

 

DJCT_Watt wrote "to significantly change the pressure of the air, you need to either change your altitude, travel faster than sound, change your altitude, or change your temperature."
You are playing a word game. On one hand you say that you cannot create pressure, and then you add the significantly. What is significient to you in this quote? Any increase in pressure, however small will make the engine work less hard to get air into the cylinders. Experiment: I collected my handy " water column" gauge. I have 2' of 1/8" id hose as the input line, and connected an adapter at the end to increase the collecting area to about 5/8" id (kind of like a very small funnel). I was about 2" from the intake of my funnel. I blew at the "funnel" and it was amazing, it moved to about 1" WC. That is an increase! and, no I was not blowing at the speed of sound, and no I was not changing my altitude by jumping up and down, and the air temp outside was about 95 degrees at the time, and I would estimate my breath to be right around that temp (using standard 98.6 body temperature) With this simple experiment, I made a change in air pressure, and any change to the positive, has to be a help, no matter how small. Keep the "Ram Air" going xB lovers, as long as you are not going for a "significant" increase in air pressure, or hp. Enjoy modding your car as you wish, and enjoy the time spent with it. Happy boxing.

 

Look, my goal isn't to confuse you, or to burst your bubble. I would be a punk on purpose. I'm merely stating the things that I have learned. At the speeds these cars are capable of, there really isn't much of a point to doing a HOME MADE ram air setup. My original point, was that buying a production aftermarket intake would likely yield more benefit than anything else.

But if you are going for the custom approach, than kudos to you. I have a custom intake, and I wasn't looking for HP either. I'm just making sure you understand what you are doing. And yes, I'm twisting my words, but the effects of "Ram Air" truly are negligible, especially under. . . say 150mph. You may see 1HP, if you are lucky.

Here is a link to the masters of Ram air, themselves, the Corvette gus:
http://forums.corvetteforum.com/show...5&page=1&pp=20

 

here's a direct quote:

Ram Air - Myth or Truth?
Marketers just can't resist it. Ram air! The words themselves summon up images of rushing wild beasts, or of secret military aircraft operating on futuristic principles.

Unfortunately, on most perofrmance cars, ram-air is as functional as tail fins were on cars of the ’60s.

What is it? Ram air just means using a forward-facing air intake to gain some extra intake pressure. We have all, as children, felt the pressure of moving air on our hands when we held them out the window of the family car. When moving air is brought smoothly to rest, the energy of its motion is converted into pressure. Motorcycles went through a "ram-air" period in the early 1990s, during which street bikes were equipped with the forward-facing "rocket-launcher" engine air intakes seen on many road-racing machines.

While it's appealing to imagine the forward velocity of a car being converted into free supercharge, the actual air pressure gain is extremely small at normal speeds. For example, at 150 mph, the pressure gain when air is efficiently brought to rest is 2.75 percent. Because this is a dynamic effect, it is proportional to the square of the air velocity. At a more realizable automobile speed of 75 mph, the effect (again with 100 percent efficient conversion of velocity into pressure) will be only one-quarter as great — that is, just under seven-tenths of one percent.

In fact, velocity energy is not converted into pressure at 100 percent efficiency. A figure of 75 percent efficiency is usual, which reduces our notional ram-air gain at 75 mph to one-half of one percent.

Therefore, at normal speeds, ram air is a myth. However, something much more interesting lies behind it, ignored by the advertiser's busy pen. That something is airbox resonance.

In order to implement ram air, the carburetors or throttle-bodies of our engine must seal to an airbox whose volume is large enough that the intake cycle of one cylinder cannot pull its internal pressure down significantly. Box volume is typically 10-20 times the engine's displacement. Then the forward-facing air intake is connected to the box. When this assembly is tested on the dyno — even without an external fan to simulate the high-speed rush of air past the intake — it is discovered that the engine's torque curve is greatly altered, with new peaks and hollows.

Why? The answer is airbox resonance. If you hold the mouth of an empty bottle near your open mouth as you loudly hum scales, you find that at certain “hum frequencies” the bottle reinforces your humming, which becomes louder. What is happening is that the springy compressibility of the air in the bottle is bouncing the slug of air in the bottle's neck back and forth at a particular frequency — higher if the bottle is small, lower if it is larger. Your humming is driving a rapid plus-and-minus variation of the air pressure inside the bottle.

The same thing happens inside a resonant airbox. The volume of air in the box is the “spring” in this kind of oscillator. The mass of air in the box's intake pipe is what oscillates. The “humming” that drives the oscillation is the rapid succession of suction pulses at the carb or throttle-body intakes. If the volume of the airbox and the dimensions of the intake pipe(s) are correctly chosen, the airbox can be made to resonate very strongly, in step with the engine's suction pulses. The result, when this is done correctly, is that the engine takes air from the box only during the high-pressure part of its cycle, while the box refills from atmosphere through its intake between engine suction pulses. This produces a useful gain in torque.

Using this idea, motorcycle engines have been able to realize torque increases, in particular speed ranges, of 10-15 percent. In race engines, it is usual to tune the airbox to resonate at peak-power rpm to increase top speed. For production engines, it is often more useful to tune the box resonance to fill in what would otherwise be a flat-spot in the torque curve, resulting in smoother power and improved acceleration.

Early resonant airbox systems used long intake pipes that terminated in forward-facing intakes. More recent designs do not connect the ram-air pipe to the box at all, but terminate it near the airbox entry. The actual entry pipe is a short piece of tubing with bellmouths on both ends. This is done because (a) the potential gain from actual ram air is too small to worry about, and (b) it's easier to tune the airbox with a short tube.

Where vehicle speeds are very high, gains from ram air are significant. This was discovered by Rolls-Royce in the late 1920s as the company developed its R Schneider Trophy air racing engine. At speeds above 300 mph, it was noticed that the R’s fuel mixture leaned out enough to cause backfiring. When the mixture was corrected for ram-air pressure gain, the engineers realized they had a "free" source of power. At 350 mph the gain from ram air is almost 15 percent. Similar mixture correction is necessary when ram air is used on drag-race and Bonneville cars and bikes.

Intuition suggests that a forward-facing intake made in the form of a funnel, large end foremost, should somehow multiply the pressure of the air, resulting in a much larger pressure gain at the small end. Sadly, intuition is wrong. In order to convert velocity energy into pressure, the air has to be slowed down, and this requires a duct that widens rather than narrows. Next time you fly on a commercial airliner, note that its engine intakes widen as the airflow approaches the compressor face. Such widening passages are called diffusers, and they are universally used in the conversion of velocity into pressure.

Language often plays tricks on us — especially when language is used by product advertisers. "Ram air" sounds much more appealing than "resonant airbox." Nevertheless, it is airbox resonance that actually generates a significant power gain.

 

As you can see, building an intake is much more complicated than slapping on a filter. There are real scientific principles behind the process, more than paper cones and "high flow" yellow foam filters.

Remember, that by building a custom intake, if you do not properly tune it, it will probably decrease your output, but it will probably sound real cool. But if you are doing it for the sake of customization, good for you. I, in fact encourage it. But remember, butt dyno's are not reliable.

Again, for those who are interested in power, ram air (at least home made) is not the way to go. The best method, is to get a good intake (pre fab), and vent the hell out of it.

 

imagine the trans am, with its huge ugly a** ram air hood. one has to drive the car 150mph before even a half of a psi is reached inside the intake manifold.

ram air is definitely not worth it.

there is definitely a lot to be said about properly tuning an air system.

-jon

 

Any pressure increase is an increase. I am not expecting even close to 1 psi, (they have electric superchargers that pull around 60 amps, and all they claim is 1 psi. But again, any small increase is a small increase. As for the cost of the xB ram air. Mine cost nothing but time, and I enjoyed that time with my xB. It is called "fun". Enjoy the box

 

Again, you guys are really taking this personally. . . and it's nothing personal.

You may see a pressure increase, but by butchering the stock box, you are going to reduce air flow, which will ultimately hurt you. Read the article I posted. . . if you are going to put in the effort to build this thing, you might as well spend 5 minutes reading a technical article.

Furthermore, the e-ram is a joke. I can give you a link if you like, that breaks it down technically, but it would require far more than 60 amps to provide 1psi into a motor.

 

I think lots of folks are confusing "ram air" with "cold air" on these intake systems, myself included. Based on the technical postings in here, I'd have to agree that what most people are referring to in here are "cold air" and not "ram air". I replaced the stock intake piece into the airbox, which was positioned behind the left headlight with a very tiny opening. I got some 3" diameter flexible aluminum ducting, and routed it to the left corner of the middle grill. My thinking is this will definitely draw in colder outside air, compared to the stock location inside the engine compartment. Colder outside air has got to be better than the heated air inside the engine compartment...
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