As I posted elsewhere, this is complete absurdity. The only attempt to give any kind of meaningful measurement at all was regarding fuel mileage. And even that is suspect, considering how much BS and pure conjecture is spewed in the rest of the story. Home made strain gauge to measure air flow? Give me a break.
"Final Project Conclusions: I finished all the projects by mid December 2001 and have the Quad Ram Air in permanently on my 1993 Dodge Shadow 2.2L NA. The K&N filter, Quad Ram Air, heavily modified air box, and crankcase vent mod / filter / ram all work together very nicely for a huge gain in performance and fuel economy. I saw a 57.9% increase in fuel economy (but I wasn't getting the stock EPA fuel economy rating, it nets a 20% improvement over the EPA rating). Horsepower based on 1/4 mile time says I gained 36.6% (34 HP), which I account mainly to the very poor breathing of the stock 2.2. My mods to my car may be a little severe for some people, and like every mod on a car you are trading off one thing for another.
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11:50 PM
84fiero123 Member
Posts: 29950 From: farmington, maine usa Registered: Oct 2004
like i said in the last post you dont belive motors manual spec. then. you think im just here too piss you off, your wrong, im just here to state some real world facts, spend 6 years in school on learn nothing about the real world, just whats in the books. seems to me every time you turn around somthing is good for you, then its bad for you, then its good for you. and all that was in books, i take it books are never wrong. engineers are idiots! read the posts on the hot rodders forum moron.
Where are the dyno sheets? What is this strain gage he used? Flow charts? Were Ambiant air temps on the days he did his 'tests' all the same or properly adjusted to standard day parameters?? No head work. No intake or exh manifold porting. No cam change. And he gets a 36.6% increase in HP with a 57.9% increase in fuel economy?
Sure, cleaning up air flow into the intake, and a less restrictive air filter will usually net a little bit, but that much? No way.
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12:37 AM
NEPTUNE Member
Posts: 10199 From: Ticlaw FL, and some other places. Registered: Aug 2001
Here ya go, I Googled it for you. Kind of long, but its all there.
The short of it is, "Ram Air" is the same difference as adding a Cold Air Intake to your car. Why did the GTO you referenced in the other thread have 10 more hp with the "Ram Air?" Well, firstly, we'll set aside the fact that its manufacturers claims, which are known to be exaggerated. Next, we need to know the exact differences between the cars. Is the only difference the "Ram Air" hood scoop? Or are there other things done to the car? Has anyone ever tested this theory by simply putting a Ram Air hood on a non-Ram Air car and taking it to the dyno to see if it makes 10 more hp? I'll bet dimes to dollars that the only thing the Ram Air GTO had going for it is that the scoop on the hood brought fresh, clean, cold air right into the air filter, whereas on the non-Ram Air cars, the air coming into the filter had to come up from under the car and get good and hot under the hood, where theres no ventilation and plenty of heat from the engine. Cold air coming straight into the filter is going combust better than hot air that had to be pulled up from under the engine.
Anyway, onto the Ram Air myth. The Ram Air Myth by Dave Rodabaugh
The Ram Air Myth is the most mythical of them all. It differs from the other myths, in that the other myths are misinterpretations of physical phenomena, whereas ram air simply does not exist.
MYTH: Use of a scoop on the front of the vehicle to collect intake air, or provide “ram air” can raise engine performance.
TRUTH: At automobile velocities, there is no ram air effect.
SIMPLE EXPLANATION
The "Truth" statement says it all. How much simpler can it be? The Ram Air effect is a total myth because it simply does not exist. “But Pontiac uses it on the Trans Am, and they know more than you do.” To those who offer this, tsk tsk. Careful reading of Pontiac’s statements on the matter reveal that the HP increase of the WS6 package are a result of a less restrictive intake, and a freer-flowing exhaust, NOT any ram air effect.
So why does Pontiac use Ram Air? Easy! To make people buy their cars! And they are quite effective with this strategy.
DEEPER EXPLANATION
Of all of the applied sciences, fluid mechanics is among the most difficult for many people to comprehend. It is a relatively youthful applied science as well, meaning that it has not had two or three centuries of work to mature into an applied science on par, with say, chemical combustion. To make matters worse, it is mathematically defined almost entirely by experimentally-determined mathematics.
This last point is the true differentiator between those who only understand concepts, and those who can quantify what they are discussing. Truly, quantification is the real skill of the engineer. It is one thing to speak about qualitative issues (the “what” of the physical sciences); it is entirely another to quantify them (the “how much” and “to what extent” of the same). In grade school, students are first taught about “closed form mathematics” and then that these mathematics are typical of scientific expression. A good example of this is Newton’s famed “law of action and reaction”, the mathematical expression of which is a succinct F=MA. So straightforward. So simple. Three variables in perfectly-defined harmony. Given any two of them, the third is easy to nail down.
Unfortunately, a vast, vast majority of the mathematics used in engineering are NOT closed form. Instead, they are multi-variable correlations valid only for a narrow set of circumstances. Deviate from those narrow circumstances, and a new expression must be experimentally derived. Fluid mechanics is almost entirely defined by these experimentally-determined expressions, further muddying an applied science not well understood.
And if there ever were an applied science for which common sense is wholly inappropriate, it is fluid mechanics. Virtually nothing obeys the “common sense” rules of observation, explaining why those who believe in ram air have extreme difficulty in believing that is simply does not exist.
The Deeper Explanation begins with a basic explanation of engine principles. Air and fuel must be combusted at a specific ratio, namely, 14.7 parts air to 1 part fuel (this is a chemical ratio). Stuffing more fuel into the cylinders without increasing the amount of air they also swallow will get no gain whatsoever. So the hot rodder’s adage “more air = more power” is proven correct. Figure out a way to stuff more air into the cylinder at any given RPM and throttle setting, and you can burn more fuel. Since burning fuel is what makes power, more air truly does create more power.
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.
Just how would this increase in pressure at the throttle plate occur? The oft-wrong “common sense” says, “If a scoop is placed in the airstream flowing around the vehicle, the velocity of the air ‘rams’ the air into the scoop, thus increasing the pressure.”
Why is this incorrect? There are two types of pressure: static and dynamic. Placing of one’s hand in front of a fan, or out of a moving car’s window, clearly exerts a force on the hand as the air diverts its path to flow around it. Most people would say “See? This is a clear indication that ram air works. Clearly there is pressure from the velocity of the air.” Well, this is correct, but only to a point. This is an example of dynamic pressure, or the force any moving fluid exerts upon obstacles in its path as the gas is diverted around the obstacle.
What an engine needs is static pressure. This is the pressure the same fluid exerts on any vessel containing it at rest. For those who were physics/chemistry geeks, it is the pressure caused by the force of the molecules bouncing off of the walls of the container. The key to understanding the difference between static and dynamic pressure lies in the velocity of the gas. Dynamic pressure is only a momentum effect due to the bulk motion of the fluid around an obstacle. Static pressure is an intrinsic property of a gas or fluid just because the molecules of the fluid are moving around. Any fluid which is moving can have BOTH dynamic and static pressure, but a fluid at rest only has static pressure.
The point of ram air would be to increase the static pressure, which would correspond to an increase in the in-cylinder air density, and of course, more air. Superchargers and turbochargers do what the mythical ram air purports to do. A supercharger trades the power of the belt and uses it to compress the air in the intake tract. This energy trade-off results in an increase in intake air pressure, more air in the cylinders, more fuel burned, and more power. A turbocharger trades the power of the hot gases and uses it to compress the air in the intake. The overall effect is the same – an increase in intake static pressure.
For ram air to work, it would have to trade the energy of the air’s velocity (as the vehicle moves through the air) for an increase in static pressure (since static pressure is a part of a gas’s internal energy, we see this is TRULY a trade in kinetic energy for an increase in internal energy). Now for the true reasons why ram air is a myth:
- The way for air velocity to be traded for an increase in static pressure is to actually SLOW IT DOWN in a nozzle of some sort. This is easily the MOST counterintuitive part of fluid mechanics for most people. The “common sense” mind says “In order to increase the pressure of the intake, the velocity of the air needs to be increased, just as increasing the speed of a fan exerts more force upon the hand.” Not only does this confuse dynamic with static pressure, but is also misses the point, which is to trade the kinetic energy of the gas for an increase in internal energy. How can this trade occur if the kinetic energy of the gas is increased? It cannot, and in fact, the only way to trade it is to use the velocity of the gas to compress itself – by slowing it down.
- Below about Mach 0.5 (or about half the speed of sound), air is considered “incompressible”. That is, even if the correct nozzle is selected, and the air is slowed down (the official term is “stagnated”) there will be zero trade. No kinetic energy will be traded in as work capable of compressing the air. The reasons for this are not discussed here; the reader may consult any reputable fluid mechanics textbook for confirmation of this fact. In plain English, a car is just too slow for ram air to work.
Still not enough evidence? Here is a little test. For ram air to work, the nozzle must be of a specific shape. The “Holley Scoop” for the Fiero is the wrong shape, by the way. The fact that it has no net shape at all immediately means it cannot effect any kind of energy trade off, so it cannot possibly create ram air. This is also true for the hood scoops on the Pontiac Firebird WS6 package as well, by the way.
What shape must it be? There are two kinds of nozzles. Pick one:
- Converging. This nozzle gets smaller as the air flows through it. It has a smaller exit than entrance. If the nozzle were a cone, the fat end is where the air would enter, and the narrow end is where it would exit.
- Diverging. This nozzle is opposite the other; it gets bigger as the air flows through it. With a larger exit than entrance, the narrow end of the cone is where the air would enter, and the fat end is where it would exit.
So, which is it?
Without hesitation, most of the “common sense” crowd will answer “Converging.” BZZZZT! Thank you for playing anyway! We have some lovely parting gifts for you! Bill, tell ‘em what they’ve won….
The answer is “divergent”. Yes, the nozzle would have to shaped so that the skinny end is pointed into the air stream, and the fat end connects to the throttle plate. How can this be right? Remember, to increase the static pressure of the intake air (which is the true “ram air” effect), the kinetic energy of the air must be traded to compress the air. This is done by slowing the air down, or stagnating it, and the only way to do this is with a diverging nozzle. Ah, but since air is incompressible at automobile speeds, it doesn’t matter any way.
Conclusion
Ram air is a myth because it does not exist, for the following reasons:
- Air is incompressible at any automobile speed., meaning that the kinetic energy of the air cannot be used to compress the air and raise the static pressure.
- The “ram air” nozzles commonly employed on automobiles tend to be the wrong shape. A divergent nozzle is required for ram air. Straight-profile scoops cannot provide a ram air effect.
Select one of the two types of intakes, warm air, or cold air. Beyond that its just about looks.
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03:03 AM
hugh Member
Posts: 5563 From: Clementon,NJ,USA Registered: Jun 2000
...i am also on the hotrodders forum, lots of older guys that know what they are doing and they are all agreeing with me....
engineers are idiots with degrees, the real world is where it matters not on a peace of paper, blueprint, computer screen. you dont belive me ask these guys.
Yeah. I guess those very nice older guys designed the keyboard and computer where you are typing and the car you are driving too. LOL! This is the best supporting argument I have ever seen in this forum. I wonder what they could do if those idiots with degrees were as smart as those hotrodders....
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08:55 AM
Oreif Member
Posts: 16460 From: Schaumburg, IL Registered: Jan 2000
Here ya go, I Googled it for you. Kind of long, but its all there. ......
The problem with the article is it "assume's" that "Ram Air" as used by the automotive industry means the same thing as it does in the aeronautical industry. It does not. Ram air in terms of Pontiac (for example) was their term for a better flowing intake manifold and heads that utilized cooler outside air from a sealed aircleaner. It never was stated anywhere that it provided any compression of air or pressure boost. Most cars will gain a benefit from adding a "Ram Air" scoop onto the car. The only reason for the gain would be a less restrictive air filter intake flow and the cooler air.
One of the reasons the Holley side scoop on a Fiero seems to feel better is because the air intake gets cooler air. So the MAT sensor reads the incoming air temp and adjusts the A/F ratio to be correct. Since cooler air is denser, the ECM makes timing and fuel adjustments to maintain the proper ratio. This makes the trottle response feel better and at highway speeds does increase gas mileage. As for measureable power increase, You will see a small horsepower increase, but again this is because of the cooler air temps not boost.
In the original article that started this thread, He basically reduced intake restrictions and provided cooler air temps. His 20% gas mileage increase is very possible. Say the EPA rating on his car was 20mpg on the highway, Reducing his air filter restriction and using cooler outside air he gained 4mpg on the highway. That is a 20% increase. He also states the engine runs a little cooler and the under hood temps are cooler. So his power and mileage increases were from removing restrictions and cooling things down Not "boost". I bet if he had dyno'd the car before and after he would find out he didn't get a 34hp gain, But he most likely he made the engine flow better, especially at the higher RPM range which did increase his power. Or more properly stated, caused him to have less power loss at higher RPM's due to the intake restriction of the stock set-up.
[This message has been edited by Oreif (edited 08-22-2005).]
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09:19 AM
PFF
System Bot
Scott-Wa Member
Posts: 5392 From: Tacoma, WA, USA Registered: Mar 2002
"Final Project Conclusions: I finished all the projects by mid December 2001 and have the Quad Ram Air in permanently on my 1993 Dodge Shadow 2.2L NA. The K&N filter, Quad Ram Air, heavily modified air box, and crankcase vent mod / filter / ram all work together very nicely for a huge gain in performance and fuel economy. I saw a 57.9% increase in fuel economy (but I wasn't getting the stock EPA fuel economy rating, it nets a 20% improvement over the EPA rating). Horsepower based on 1/4 mile time says I gained 36.6% (34 HP), which I account mainly to the very poor breathing of the stock 2.2. My mods to my car may be a little severe for some people, and like every mod on a car you are trading off one thing for another.
Wonder if he can do math... or just how bad a shape the car was in before these mods and was maybe an oil change and tuneup done at the same time?
"Results: More power across the board, a little deeper tone, and if you stand up to six feet in front of the car and someone slams on the gas in neutral you can feel the pull from the dual intakes. The high speed acceleration was increased much more than the low speed acceleration (which one would except since more air would be flowing into the dual intakes at 50 MPH then at 0 MPH). Another benefit, a huge increase in fuel economy, a 5.1 MPG increase."
That's funny... standing 6 feet in front of car you can feel the pull. Good thing he wasn't 3 feet in front, might have sucked him into the engine.
A 5.1mpg increase is a 57.9% increase in mileage? My Turbo 2.2 Newyorker gets 27.9mpg average, a 57.9% increase would put me at around 44 mpg. He started with 8.9mpg for that to add up and ended up with 14mpg. My car got over 17mpg average city/highway with the timing belt off a tooth.
Not much in that writeup makes much sense. The factory air cleaner setup on those engines were a horrible looking design and a less restrictive setup may help a lot, but I don't see it making any mileage improvements and doubt he got more than a 10% increase in max power out of it in the top end range of the 1/4 mile.
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09:25 AM
Scott-Wa Member
Posts: 5392 From: Tacoma, WA, USA Registered: Mar 2002
Here ya go, I Googled it for you. Kind of long, but its all there.
The short of it is, "Ram Air" is the same difference as adding a Cold Air Intake to your car. Why did the GTO you referenced in the other thread have 10 more hp with the "Ram Air?" Well, firstly, we'll set aside the fact that its manufacturers claims, which are known to be exaggerated. Next, we need to know the exact differences between the cars. Is the only difference the "Ram Air" hood scoop? Or are there other things done to the car? Has anyone ever tested this theory by simply putting a Ram Air hood on a non-Ram Air car and taking it to the dyno to see if it makes 10 more hp? I'll bet dimes to dollars that the only thing the Ram Air GTO had going for it is that the scoop on the hood brought fresh, clean, cold air right into the air filter, whereas on the non-Ram Air cars, the air coming into the filter had to come up from under the car and get good and hot under the hood, where theres no ventilation and plenty of heat from the engine. Cold air coming straight into the filter is going combust better than hot air that had to be pulled up from under the engine.
Anyway, onto the Ram Air myth. The Ram Air Myth by Dave Rodabaugh
So who is this Dave Rodabaugh? Ram air is usually a marketing gimmick, but the concept of putting a scoop (ram air) in the high pressure area under the front end, behind the grill, in place of headlights, or taking the air off the high pressure area of the windshield (much more on pre 80's cars) sure seems to have worked for power at the track. You got a colder denser air charge than what is available under the hood, and all the mumbo jumbo talk in that article really doesn't seem to add up to squat except that he's changing the definition maybe. I can't think of a car built today that doesn't duct it's air in from a high pressure area outside the engine bay.
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09:34 AM
84fiero123 Member
Posts: 29950 From: farmington, maine usa Registered: Oct 2004
ok so where are your dyno test, you say thast engineers are the know alls where are there test. everything you show me has no back up eather. so i guess a mileage increase is not anything. remember the guy in his garage had no degree, but he made wang. or did we forget that. computers are great when they work. not all emgineering is foolproof. and the tests done by the manufacturers in the 60' down played the horse power ratings, if you look at any of the dyno test on these cars made by owners you will see that. just because its not on the idiotnet, or in a book its not true? nothing against the new tec but if the oil companys wanted our money they have it, and are getting more and more everyday. they dont have any reason to want us to buy anything that would give us better mileage. and yes the ram air systems were closed right over the carbs, if you dont belive me look at those cars next time you are at a show. but i guess if it doesnt have a computer in it it cant do anything right boys? let me tell you a little story. i used to work for a general motors assembly plant from 73 to 90. one morning on the way in i stoped at the cafateria to get something to eat . i saw my dad sitting like he did every morning, eating his eggs and talking to some friends. i grabed my food and went over to sit with them, and see what was up. one guy, i forget his name, was saying how he just got back from Maine, he had spent the weekend at moosehead camping, a 5 hour drive each way, about a 300 mile ride each way. he had just got his new buick regal the week before. he drove up and back and still had a half of a tank of gas in his car, he never put any gas gas in. i said he was drunk all weekend and didn't remember filling up, he was a friend of my dads and i figured he was just anouther drunk, dad said no he never drinks never had. i said sure ok. not beliveing anyone i went to work, day shift. at the end of the day when everyone left work, 2000 or so men and women. this guy was standing in the parking lot with his hood up, no carb under the hood, now the plant parking lot has security in it, and i meen you have to drive by a guard to get in the lot, and there are guards that patrol the lot. but no one saw anyone under the hood of his car, no one saw anything, no if you figure that out it comes to somewhere around 60 miles to the gallon, the next day after leaveing his car there there was a new carb under the hood and no one saw anything again. the best we can figure is it was an experimental carb that wasnt supposed to be on the car and when they found out they removed it but didnt have time to do it before getting seen. belive what you want guys. i saw it. you have shown me nuthing from any source except the idiotnet, and those were not verified. i showed you proof from a motors repair manual, from the manufacturer, if i could find the car and driver articles i would but they are not on the idiotnet. like my signature says technology is great when it works and one big pain in the ass when it doesnt. just out of curiosity how old are you guys? that you only belive what you read on the idiotnet.
------------------ technology is great when it works and one big pain in the ass when it doesnt. Detroit iron rules all the rest are just toys.
[This message has been edited by 84fiero123 (edited 08-22-2005).]
The big4 Japanese motorcycle manufacturers all use a ram air system on their top sport bikes to pressurize the air box at speed. A test by Sport Rider magazine found about a 6% increase in hp due to the ram effect. They used pressure instruments while riding to see how much pressure difference the ram air systems made in the airbox, then they duplicated the pressure increases with the bikes strapped on a dyno by blowing air from a huge compressor at the intakes. Keep in mind that these bikes make most of their power above 9000 rpm and redline around 13,000 rpm. I doubt if it would have that much effect on a car that runs below 6000 rpm.
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10:09 AM
RACE Member
Posts: 4842 From: Des Moines IA Registered: Dec 2002
Whey are we even reading about a ****** Dodge. When I saw that test "vehicle" the guy lost all credibility. This guy is not a rocket scientist. Don't forget that 90% of all statistics are made up to support claims.
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11:13 AM
Scott-Wa Member
Posts: 5392 From: Tacoma, WA, USA Registered: Mar 2002
Hehe, I knew a group of guys, one was always boasting about his mileage and wanted to try one of those adders. After he installed it, the guys in the motorpool started adding a gallon of gas to his car every couple of days (Hey gas was under a buck a gallon). After a couple of weeks he was 'getting' 50 then 70+ mpg. Boasting like a rooster in a barnyard. So they tapered it off after a couple of weeks and then started siphoning a gallon here and a gallon there. Even though he was at the gas station every other day now... think his 'mileage' dropped? Wasn't a new idea back then, but some people wanted to help his cow magnets.
It's amazing how in all these 100 mpg carb stories no one can produce one even from the plans on the internet.
I know how the guy you know got his mileage... he was heading south on that trip and if you look at a globe, that's all downhill! ;-)
A 100mpg+ carb is doable... just don't expect 200 hp, air bags, a/c, a covered body, heater, stereo etc. Briggs and Stratton Buckboard got over 200mpg in 1917, but it also probably topped out around 20-30mph and might have needed a push going up a hill. I've been thinking about building a more modern version of that.
Here is a link to some kids that built a 331mpg vehicle in 1998
Originally posted by Oreif: One of the reasons the Holley side scoop on a Fiero seems to feel better is because the air intake gets cooler air. So the MAT sensor reads the incoming air temp and adjusts the A/F ratio to be correct. Since cooler air is denser, the ECM makes timing and fuel adjustments to maintain the proper ratio. This makes the trottle response feel better and at highway speeds does increase gas mileage. As for measureable power increase, You will see a small horsepower increase, but again this is because of the cooler air temps not boost.
Never had a Holley scoop on the side of my Fiero, so I don't know anything about the effectiveness. But doesn't it sit over the stock intake opening? Why would the air be cooler?
GL
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02:22 PM
Scott-Wa Member
Posts: 5392 From: Tacoma, WA, USA Registered: Mar 2002
I don't know if anyone ever meant for the holley scoop to be more than a looks thing. It may stick out enough to disrupt airflow enough but then again, any extra pressure gained would probably be offset by it's aerodynamic drag.
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03:36 PM
Fastback 86 Member
Posts: 7849 From: Los Angeles, CA Registered: Sep 2003
Some of you are still missing the basic principle here. What "Ram Air" or whatever the manufacturer wants to call it does is give the car a better designed air intake. In most cases, its a straight tube that goes from the hood or grill straight into the air filter and then straight into the throttle body. Nice and simple. Now, take a look at any non-Ram Air car. My dads Grand Am doesn't have Ram Air, so I'll use it as an example. In fact, it has the most convoluted intake system I've ever seen. The tube starts on the passengers side of the car, runs up and across by the radiator, back down into the air box, then up and around a few bends to the throttle body. Thats a huge amount of plumbing that the engine has to pull air through. Every twist and turn and change in tube shape and diameter decreases air velocity, making it that much harder for the engine to pull the air in. A "Ram Air" type system would eliminate all that and use an intake tube that was as large in diameter as possible, used a free flowing air filter, and was a straight as possible (minimal twists and turns). You can do the same thing by picking up a K&N Cold Air Intake from Kragen or eBay. Its all the same idea: bring cold air in as quickly and efficiently as possible, which translates into a little more power.
I would also like to point out the velocities. Throttle bodies at WOT are moving several hundred cubic feet of air per minute. To move that much air through that little hole, its gotta be moving REALLY fast. Much faster than your car will ever get going. So, your "Ram Air" will help in the sense that the air will already be moving into the engine, so the engine won't have to pull static air in. It makes a little less work for the engine, which can translate into a little more power.
If you can, take a look at any "Ram Air" system. Take the Camaro or Firebird as an example. Go pop the hood on a late model F-Body and look at the bottom of it. Those big ol' scoops aren't helping you at all, because the air going in the scoop is going into some very narrow tubes, and must then make some very sharp turns to get ducted back to the front of the engine and the rest of the air intake. Its all looks, its not helping your engine at all. Those scoops are more drag than anything.
Finally, the Holley Fiero scoop doesn't do squat. I've had one, its all for looks.
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03:48 PM
84fiero123 Member
Posts: 29950 From: farmington, maine usa Registered: Oct 2004
ever see a water line coming from the street to your house, its large like 10" or better then it goes down to 1" so you have a constant amount of pressure in the sink or shower. same idea. take a 4" hole go down to the 2" inlet the pressure rises in the 2" compared to the 4"simply open up the hole in the side to 4" put a scoop on it and run the 4" pipe into the air cleaner canister, its a sealed unit. put a low restriction air filter in the canister. get my drift.you have a sealed streaight as possible line to the intake. nascar has been useing cowl induction and ram air for years, so i take it they dont know what they are doing either.
------------------ technology is great when it works and one big pain in the ass when it doesnt. Detroit iron rules all the rest are just toys.
[This message has been edited by 84fiero123 (edited 08-22-2005).]
The one thing I notice about all this discussion (in particular the lengthy description of fluid dynamics) is that it seems the debate is dealing with positive air pressures only, and whether a ram air intake can "compress" air enough to affect improvements in performance. Aside from the fact that the term mostly applies to intake configuration and colder air intake, when it comes to normal aspiration, you aren't actually dealing with just positive air pressures, you're dealing with a vacuum as well. So it seems the argument isn't "will a ram air intake increase air pressure"....it's, "will ram air DECREASE vacuum above the throttle plate". They are definitely not the same thing.
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06:31 PM
sanderson Member
Posts: 2203 From: corpus christi, texas, usa Registered: Sep 2001
And some stupid engineer didn't understand this and accidentally built a carburetor that sucks in fuel.
BTW, 84fiero123 what is your chosen profession so I will have class of people to insult next time I decide to rant?
no insults just facts
i have been an ironworker/welder/fabricater for the last 15 years. worked with dozens of different engineers over the year and the ones i'm bitching about are the one with just school, book learning. they don't spend anytime in the field," it works on paper " or " the computer says it will work" are my favorite lines used by them. over the years i have met 2 or 3 that spent a few years in the field working building the things they were going to engineer. they understood how things work and would help you when something they drew up didnt work. the others just blamed the man who built it. i'm not saying they are all bad or dont know what they are doing. i also spent 15 years at general motors building cars. those were my favorites they would stand there and say " it works on paper, why can't you make it work." even when they came down to the line and saw that it didnt work they would still say that. but back to the subject so how about it has anyone looked at the 1970 Motors Manual and seen the rateings for the ram air and the standard engines. there is a 10 hp difference. or because its not on the idiotnet can't anyonr belive it. oh i forgot it wasnt stated by an engineer.
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11:41 PM
Marvin McInnis Member
Posts: 11599 From: ~ Kansas City, USA Registered: Apr 2002
I will concede to you that 50% of all engineers are below average, but nothing more. Philosophically speaking, one of an engineer's main jobs is to administer the laws of physics. And no matter how much you may want it to be otherwise, the laws of the universe ... at least with respect to the physics of everyday phenomena ... are both well known and rigidly enforced. Real engineers know that.
[This message has been edited by Marvin McInnis (edited 08-22-2005).]
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11:48 PM
Fastback 86 Member
Posts: 7849 From: Los Angeles, CA Registered: Sep 2003
so how about it has anyone looked at the 1970 Motors Manual and seen the rateings for the ram air and the standard engines. there is a 10 hp difference. or because its not on the idiotnet can't anyonr belive it. oh i forgot it wasnt stated by an engineer.
Big freakin' deal. No one said you were wrong about the Ram Air optioned car having 10 more horsepower. What we've been saying, if you've read this thread, is that Ram Air is a broad marketing term used to sucker people in. The Ram Air package is more than a hood scoop. Go back and read Oreif's post.
Engineers are the bane of my life. There's a stack of ECOs (engineering change orders) turned in from the plant floor everyday. They take great pains to take their hole spacing out to 4 decimal places to make all their measuments work out to last digit---then call for a 1/4" hole size on the print when there's going to be a 5/16" bolt going thru it. Most times, the cnc operators catch it--sometimes not. Sometimes, it's torn the spindle right out of the head. Good operators can make an engineer look good--or like squat.
[This message has been edited by maryjane (edited 08-23-2005).]
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12:34 AM
84fiero123 Member
Posts: 29950 From: farmington, maine usa Registered: Oct 2004
Big freakin' deal. No one said you were wrong about the Ram Air optioned car having 10 more horsepower. What we've been saying, if you've read this thread, is that Ram Air is a broad marketing term used to sucker people in. The Ram Air package is more than a hood scoop. Go back and read Oreif's post.
actually yes in the beginning of this everyone said i was and wanted proof, dyno tests, now that they see i was right they are upset about my dislike for engineers. so be it, i have to deal with them every day myself and know a good one from a bad one, and can be saved by a lowly minor employee, like myself,but why should i have to take the heat or bull from one who has no idea what they are doing and are gettting paid double what i am, but the point of the original post was how to improve the flow of the intake thats on the fiero without putting on a $600 intake. i belive ram air would improve the air flow, it may be minor but it will improve it in the 4 to 6 k rpm range.
------------------ technology is great when it works and one big pain in the ass when it doesnt. Detroit iron rules all the rest are just toys.
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07:54 AM
Oreif Member
Posts: 16460 From: Schaumburg, IL Registered: Jan 2000
but the point of the original post was how to improve the flow of the intake thats on the fiero without putting on a $600 intake. i belive ram air would improve the air flow, it may be minor but it will improve it in the 4 to 6 k rpm range.
I think you are in the wrong thread. The original post was asking what we thought of what a guy did to a Dodge Shadow. I don't see any mention of adding a Ram Air vs a $600 intake manifold. Yes adding a scoop will improve the Fiero at speed by maybe 1hp, But the intake manifold swapped to a better flowing one will give you improvements and will actually be felt and measured on a dyno.
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09:38 AM
84fiero123 Member
Posts: 29950 From: farmington, maine usa Registered: Oct 2004
I think you are in the wrong thread. The original post was asking what we thought of what a guy did to a Dodge Shadow. I don't see any mention of adding a Ram Air vs a $600 intake manifold. Yes adding a scoop will improve the Fiero at speed by maybe 1hp, But the intake manifold swapped to a better flowing one will give you improvements and will actually be felt and measured on a dyno.
this started in the tech section under Porting the Fiero intake and because it was getting heated and probably pissing some people off that love the $600 trueleo intake, someone brought it here useing that particular post to start this, you know i really dont care if you what you think of the first post on this thread. it was just one of the first example i found to support ram air as a viable option to that waste product of a manifold. i say it looks ugly and isn't worth the money, the increase is in the upper rpm range where the ram air would give you incresed air flow threw the stock intake. but i said the trueleo was ugly and overpriced, and of low quallity. i upset a lot of people who wanted me off the tech subject. and as far as engineers go ya there are some good ones out there but most of them dont know what there doing because they never did any real work in there field. maryjane gave a good exaple and if you go back to the tech section you will see how this started.
------------------ technology is great when it works and one big pain in the ass when it doesnt. Detroit iron rules all the rest are just toys.
[This message has been edited by 84fiero123 (edited 08-23-2005).]
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05:14 PM
Fastback 86 Member
Posts: 7849 From: Los Angeles, CA Registered: Sep 2003
this started in the tech section under Porting the Fiero intake and because it was getting heated and probably pissing some people off that love the $600 trueleo intake, someone brought it here useing that particular post to start this, you know i really dont care if you what you think of the first post on this thread. it was just one of the first example i found to support ram air as a viable option to that waste product of a manifold. i say it looks ugly and isn't worth the money, the increase is in the upper rpm range where the ram air would give you incresed air flow threw the stock intake. but i said the trueleo was ugly and overpriced, and of low quallity. i upset a lot of people who wanted me off the tech subject. and as far as engineers go ya there are some good ones out there but most of them dont know what there doing because they never did any real work in there field. maryjane gave a good exaple and if you go back to the tech section you will see how this started.
But Ram Air is NOT a viable alternative! Why is that so hard to understand? Take your Ram Air GTO as an example - 10 more horsepower than the non-Ram Air car. Now take the Trueleo intake - dyno proven 14 horsepower over the stock intake. Thats 4 more than your precious Ram Air. Yes, I realize I'm comparing apples and oranges now, but nothing else seems to be getting through.
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10:02 PM
PFF
System Bot
sanderson Member
Posts: 2203 From: corpus christi, texas, usa Registered: Sep 2001
I did some pressure drop calculations today. Cooling the inlet air from 120 'F to 80 'F would result in about 3.5% more air flow for the same pressure drop through the manifold. This would result in about 5 HP on a 140 HP engine. So a cold air intake can get reasonable gains vs an intake that is sucking in underhood air.
At 140 HP the required airflow is about 220 cfm. The velocity in a 3" air intake at 220 cfm is about 77 feet per second or 50 miles per hour. This sounds high but there is almost no pressure loss in accelerating from stagnant conditions to 50 mph to get into the air inlet. I calculate about 0.5" H2O of pressure loss which is less than 0.02 psi. You save this by amount by driving down the road at 50 mph with your air intake in the direction of travel. This trnaslates into well under 1 HP of addtional air flow.
As has been previously stated more than once "ram air" is all about ensuring cool air to the engine and the "ram" effect doesn't amount to jack.
Of course I'm just an idiot engineer and this is all book learning so it doesn't mean squat.
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10:38 PM
Oreif Member
Posts: 16460 From: Schaumburg, IL Registered: Jan 2000
Take your Ram Air GTO as an example - 10 more horsepower than the non-Ram Air car.
He can't understand. The 10hp between the non-ram air engine and the ram air engine is the camshaft. It has nothing to do with the scoop or air cleaner. He thinks he can get 20hp because some kid said he got it on a Dodge Shadow.
this started in the tech section under Porting the Fiero intake and because it was getting heated and probably pissing some people off that love the $600 trueleo intake, someone brought it here useing that particular post to start this, you know i really dont care if you what you think of the first post on this thread. it was just one of the first example i found to support ram air as a viable option to that waste product of a manifold. i say it looks ugly and isn't worth the money, the increase is in the upper rpm range where the ram air would give you incresed air flow threw the stock intake. but i said the trueleo was ugly and overpriced, and of low quallity. i upset a lot of people who wanted me off the tech subject. and as far as engineers go ya there are some good ones out there but most of them dont know what there doing because they never did any real work in there field. maryjane gave a good exaple and if you go back to the tech section you will see how this started.
Actually, it was brought here to avoid cluttering the FIERO tech section thread with off topic discussion subject matter. Whether an item is worth XXX $ or not is solely up to the person buying it IMO. In your example the guy said he gained 34hp and a significant MPG increase with a simple apparatus made from a flex hose and a collector, with the only documentation being his word that he had a greatly improved 1/4 mile time. Actually, he said he calculated that HP gain FROM his improved 1/4 mile. Both the HP gain and the improved milage would have been a big marketing tool for that automaker. Those #s, are nothing to sneeze at, but if it were all just that simple, I suspect someone at the automaker would have figured it out long before that vehicle and powerplant configuration ever hit the showroom floors. A lot of people, other than engineers, test and tryout all vehicles before they are released for sale to the public.
[This message has been edited by maryjane (edited 08-23-2005).]
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11:36 PM
Aug 24th, 2005
Marvin McInnis Member
Posts: 11599 From: ~ Kansas City, USA Registered: Apr 2002
Ten or fifteen years ago I designed and prototyped an electronic airspeed indicator for aircraft use. From ... memory it seems that the dynamic pressure at 200 mph is about 1.5 psi. (This assumes 100% pressure recovery; most real-world diffusers achieve about 80% max.) Since dynamic pressure is proportional to the square of speed, the maximum dynamic pressure available at 70 mph would be about 0.17 psi ... only a little more than 1% "boost" over static conditions, even assuming 100% pressure recovery.
...
quote
Originally posted 11-21-2003 by Marvin McInnis:
The "ram air" effect is not quite a myth ... it is just highly overrated, and insignificant at automobile speeds. The term "Ram Air" (with capital letters), as used by Pontiac, means nothing; it's just a marketing gimmick.
If you do the math (dynamic pressure: P = density * V squared), you will find that the pressure boost from "ram air" will gain you a theoretical maximum of less than 2% at 200 mph ... and even that assumes a properly designed, 100% efficient intake system.
Conversely, the gains from using cool intake air rather than heated air from the engine compartment are considerable and easy to obtain. Again, if you do the math, you will find that you can gain up to 10% simply by reducing the intake air temperature from 160 degrees F (typical engine compartment air) to 80 degrees F (typical outside air). PV=nRT ... it's not just a good idea, it's the law!
The issue of intake air temperature is worth pondering for those of you who have replaced the stock Fiero cold-air intake with a cool-looking K&N filter located in the engine compartment. No flames, please. It's your car and you can do with it whatever makes you happy.
A final note: This whole discussion of pressure (with respect to power gain) is meaningless except at full throttle. On the other hand, cool intake air will increase the thermal efficiency of an engine at all throttle settings and can result in reduced fuel consumption under most driving conditions.
[This message has been edited by Marvin McInnis (edited 08-24-2005).]
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10:46 AM
84fiero123 Member
Posts: 29950 From: farmington, maine usa Registered: Oct 2004
1968 - Car of the year An extensive restyling distinguished the 1968 GTO from the previous models. Most notable was the new Endura color-keyed front bumper. The GTO was the first GM car to use this new flexible polyurethane covering that allowed minor dents to pop out without any permanent damage. Optional hidden headlights combined with the Endura nose created a handsome vehicle unlike any previous GTO. The stunning styling, powerful performance, solid engineering, and excellent market timing were all factors that helped the GTO garner the coveted Motor Trend Car of the Year award.
More horsepower was on tap for the new body style. All engines displaced 400 cubic inches, but the standard engine rose to 350 horsepower from 335 horsepower - the no-cost economy two-barrel engine gained 10 horsepower for a 265-horsepower rating. The optional HO engine remained at 360 horsepower, as did the optional Ram Air engine until March 1968, when the 366-horsepower Ram Air II option was introduced.
Considering its high-performance equipment, the Ram Air II's rating was probably conservative. It came with 10.75:1-compression forged pistons, forged steel crankshaft, new cylinder heads with round exhaust ports, free-flowing exhaust manifolds, a high lift camshaft with the corresponding high-performance valvetrain components, and a re-curved distributor. The Ram Air II put 445 lb.-ft. of stump-pulling torque to the pavement via the mandatory limited-slip Safe-T-Track rear end with 4.33:1 gears.
The coupe body style was dropped for '68. Sales were tilted heavily toward hardtops, which sold 77,704 units compared to 9,980 convertibles. The popular hood-mounted tachometer option continued from 1967, too. The Ram Air cars had 5500-rpm redlines compared to the standard 5200-rpm limit. The external tachs helped the GTO project a powerful performance car image. this is from a gm web sight. note the differences. between the ram and normal 400. granted cam and valve differences but you have to allow the engine to work all the air the ramair gets hence the changes. besides who in there right mind would just put an intake on without upgradeing the rest of the air flow threw the engine. longer duration cam larger valves to help it use all the air. and get rid of it. what goes in must go out to make any flow difference.
note the differences. between the ram and normal 400. granted cam and valve differences but you have to allow the engine to work all the air the ramair gets hence the changes. besides who in there right mind would just put an intake on without upgradeing the rest of the air flow threw the engine?. longer duration cam larger valves to help it use all the air. and get rid of it. what goes in must go out to make any flow difference
Evidently, the guy with the Dodge Shadow. Which, was exactly the point I was making about the 1st example you cited. And, you do have to ask yourself from where the improvement really came from. Was it from the ram air, or did it predominantly come from the longer duration cam, improved valvetrain, recurved dist, free-flowing exh, bigger valves, better flowing heads?
If an owner had disconnected his Ram Air from the above engine, and ran just an air filter, I suspect the improvement over the other 400 would still have been significant.
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09:46 PM
Marvin McInnis Member
Posts: 11599 From: ~ Kansas City, USA Registered: Apr 2002
... The optional HO engine remained at 360 horsepower, as did the optional Ram Air engine until March 1968, when the 366-horsepower Ram Air II option was introduced.
quote
Originally posted by maryjane:
If an owner had disconnected his Ram Air from the above engine, and ran just an air filter, I suspect the improvement over the other 400 would still have been significant.
Interesting thought, maryjane, since GM's horsepower tests are conducted on a (stationary) engine dyno, in accordance with SAE standards. Even if they were conducted on a chassis dyno, the "airspeed" would still be zero and thus any "Ram" effect would be zero during testing.
[This message has been edited by Marvin McInnis (edited 08-24-2005).]
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11:45 PM
Aug 25th, 2005
Steve Normington Member
Posts: 7663 From: Mesa, AZ, USA Registered: Apr 2001
- Air is incompressible at any automobile speed., meaning that the kinetic energy of the air cannot be used to compress the air and raise the static pressure.
If kinetic energy of air cannot be converted to static pressure, why does an aircraft airspeed indicator work below 55 mph?
