Skeedatl

Bad for an environmental control filter maybe. But you don't use automotive filters for environmental controls and vice versa.

harddrivin1le

http://www.ws6.com/ramtest.htm

Skeedatl

There are 2 types of intakes, warm air and cold air.

There is no ram effect from ram air at automobile speeds. Air isn't compressable at automobile speeds.

Any benefit from ram air comes from charge temperature, not from the magic "ram" effect.

And your dyno numbers...didn't you just get done claiming those differences are well within the error margin of the Dynojet?

Put down the magazines and get some PERSONAL experience racing and building power for a change.

Swat Dude

Nice late post after the question has already been answered. And if you don't believe surface area has an effect on pressure loss over the media, you are more ignorant than I thought.

The speed of the air, measured in feet per minute, traveling across a given media makes all the difference in the world when it comes to pressure loss.

Flanagan

Simple test:
Take two cone coffee filters. Cut one so it opens flat. Put your mouth up to it and blow/suck. You should be good at that j/k Then take the other one, stick the cone end in your mouth and do the same thing. Note the difference. Sure it's unscientific and I'm sure there are crappy engines out there that can't pull more air in even with an intake with more surface area, but the more surface area, the more flow, the better the filtration given the same output size.

Maybe we should lock you guys in the room as TLover suggested but with blunt-tipped safety scissors, a pack of coffee filters, and a high-speed fan.

Skeedatl

A little cut-n-paste happy are ya? Getting other's people's thoughts confused are ya.

How about coming up with your own? 0-60 mouse and keyboard performance isn't experience.

Put down the Hot Rod mag for 2 seconds and take your 1LE to the track (if it can make it without breaking) and make a few passes. Then go build power and go back.

How about getting into a sport before feigning expertise in it.

harddrivin1le

http://www.vararam.com/reality_of_ram_air01.html

Skeedatl

There is no such thing as ram air at automotive speeds. Air is not compressable at automotive speeds. Any benefit from ram air comes not from any mythical ram effect, but ONLY from intake charge temperature.

Take fluids and you would understand this.

Swat Dude

As usual, you are diverting off the subject at hand to try and prove you know something. No one said anything about the engines ability to inhale so many cfm's. So again you are WRONG. We were only talking about the filters pressure loss at specific RPM, which is the test you linked to. One could ASSume that the same RPM would give you the same cfm and the pressure losses occurring with each given filter could be lowered by increasing the surface. And by the way, Jack A$$, my grammar is just fine. It's my typing that is not so good.

harddrivin1le

I took fluids...

two semesters...

and you don't know what you're talking about.

REAL WORLD PROOF:

http://www.rrzone.com/929products/ra...amairexp.shtml

Swat Dude

I concur. The ASHRAE test method uses a specific dust concoction that includes specific percentages of differing size particles. This "weighted" dust is then "fed" to the filter being tested.

Flanagan

Let me start by saying I'm a designer, not an engineer, but let's do some math. I could be completely oversimplifying this and missing conversions, but you can fill in the blanks. Let's make it simple: a one liter engine. And it's a terrible one liter engine. Every cycle it can only pack that one liter of air into its cylinders. At 2000 RPM, it can flow 500 cc/minute.

Swat Dude

I've heard of magazine racers but now we have Harddrivin, a web based scientist.

Dude, I have this mental picture of you with a beard, not having bathed for a few weeks, and empty wrappers and pop cans all over the room. You are frantically typing on the computer trying to access all your links, as you frantically puff on your cigarette. Your 38 years old, jobless, and your elderly mom is yelling in the background for you to get off the computer and come rub her feet.

harddrivin1le

http://www.rrzone.com/929products/ra...amairexp.shtml

Skeedatl

Then you should know the difference between static and dynamic pressure.

Lemmie explain it slowly so you may understand it.

There isn't enough energy in the dynamic air to convert it to increased static pressure.

Here are some sample calculations.

RAM AIR

Operating Conditions
temperature = Tair = 20C = 293K
atm. pressure = Pair = 14.7PSIA
Cpair = 1005J/KgK
K = 1.4
the Cpair and K are constants for air.

Case 1 @ 100Kmh (62Mph) = 27.78m/s

Calculating temperature of the ram air

Tramair = ((Vcar^2/2gc)/cp) + Tair
Tramair = (((27.78m/s)^2/2(1kgm/Ns^2)/1005J/kg) + 293K
Tramair = 293.4K

the temperature increased by 0.4K or 0.4C.

Pram = Pair (Tram/Tair)^(k/(k-1))
Pram = 14.7PSIA (293.4K/293K)^(1.4/(1.4-1))
Pram = 14.75PSIA - 14.7PSIA
Pram = 0.05PSIG (gauge pressure)

so as you can see driving 100kmh will only have a gain of 0.05 psi! now lets try for 200kmh.

Case 2 @ 200Kmh (124Mph) = 55.5m/s

Calculating temperature of the ram air

Tramair = ((Vcar^2/2gc)/cp) + Tair
Tramair = (((55.5m/s)^2/2(1kgm/Ns^2)/1005J/kg) + 293K
Tramair = 294.5K

the temperature increased by 1.5K or 1.5C.

Pram = Pair (Tram/Tair)^(k/(k-1))
Pram = 14.7PSIA (294.5K/293K)^(1.4/(1.4-1))
Pram = 14.97PSIA - 14.7PSIA
Pram = 0.27PSIG (gauge pressure)


You haven't had fluids otherwise you would already understand this.

Swat Dude

...and ram jets are also pretty useless until MACH 1 or higher.

harddrivin1le

great,

you've just ignored every REAL WORLD test I've posted.

http://www.rrzone.com/929products/ra...amairexp.shtml

Skeedatl

And you ignored the physics behind fluid mechanics. You have NEVER taken fluids and don't understand the mathematics so you ignore them. All of these ram air tests you keep posting are subject to variables, intake charge temp, position of the intake without the ram air, etc...

The MATHEMATICS behind why the RAM in Ram Air doesn't doesn't do sh!t are indisputable.

harddrivin1le

http://www.vararam.com/reality_of_ram_air01.html

Swat Dude

Real World? Isn't that a show on MTV???? Or this case, real world usually means "gut-feel" and what's that term, Skeed, help me out here. It's been a while since college and I pretty much brain flushed all my Fluids, Thermo, Diff EQ, Mat. Analysis, etc., etc. by being a cop for 10 years. You know, when the outcome of your experiment is influenced by what you want to happen or what you think should happen. The controls in these supposed "real-world" experiments are non-existent. None this real world stuff would be accepted by any scientific journal as having any validity whatsoever.

harddrivin1le

http://www.vararam.com/reality_of_ram_air01.html

Skeedatl

The test you posted is flawed...they too confused static with dynamic pressure by substituting supercharging for dynamic air flow. Their "fan" doesn't simulate the real world. It actually compressed the air, something that DOES NOT HAPPEN with ram air.

Obviously they've never taken fluids either...but their readers are obviously too stupid to dispute their claims.

harddrivin1le

LOL

Swat Dude

VR, the leader in RAM AIR Technology???? Wow, that don't seem like they have any alterior motive. No, not at all. Show me a University study or an independent test by a recogonized laboratory.

...And so it detiorates. Harddrivin is in the fetal position now, no longer able to think. So instead of responding he goes it to repeat the link mode.

Go rub your momma's feet, Dweeb.

Skeedatl

Of course you laugh...you're a benchtop racer who takes their flawed logic of others and make it your own.

You've never taken fluids otherwise you would understand why their test (just like the bogus filter test) was flawed.

harddrivin1le

http://www.ws6.com/ramtest.htm

Skeedatl

You've never taken fluids otherwise you would understand why their test (just like the bogus filter test) was flawed.

harddrivin1le

P1V1 = P2V2

A properly designed scoop SLOWS the velocity of the air, thereby INCREASING pressure. That's why cars have HIGH PRESSURE areas.

You're ignoring that fact.

Some lights planes can achieve flight @ 70 MPH take-off speeds...

Skeedatl

Static pressure is not dynamic pressure.

You're ignoring that fact. Why am I wasting time trying to explain fluids to you.

Explaining fluids to you is like explaining calculus to a toddler.

Continue to live in ignorance.

harddrivin1le

P1V1 = P2V2

That's the principle of FLIGHT.

That last time I checked that was DYNAMIC.

You're pretending that Bernoulli's equation doesn't exist...

Yet, it does.

Swat Dude

Again, your lack of understanding of even the principles Skeed refers to screams ignorance. You are not grasping what he is saying and you two are not talking about the same things.

Skeedatl

You really HAVEN'T taken fluids. Bernoulli's principle is why airplanes fly. It has nothing to do with absolute velocity, only differences in absolute velocities and the effect on sideways pressure.

Faster moving air has less static pressure than slow moving air (another reason ram air doesn't work). The air on top of an air foil has to move faster to cover the increased distance compared to the bottom side of the wing. The faster moving air exerts less pressure on the top of the wing. This unbalanced force creates lift.

Jeez. Get educated.

harddrivin1le

And an air scoop in a well designed ram air system also results in a DROP in air velocity, which yields an INCREASE in pressure.

Skeedatl

You're right. It is dynamic, but dynamic flow exerts less "side" pressure than static air. Increases in horsepower from from increases in STATIC, NOT DYNAMIC pressures.


Bernoulli, live him, love him...

For God's sake UNDERSTAND him.

I know you're just ignorant about fluid mechanics. Go to a fluids page and study up on static vs. dynamic pressures...then come back and you'll understand what I'm talking about.

Swat Dude

Skeed,

If I may direct your attention away from Harddrivin (by the way, I think that refers to his hard disk). I take a little exception to you converting static pressure from water guage to psi. It seems like your attempt to make the impact of small changes in static pressure seem more miniscule than they are. Just for S and G's, take the attached HEPA filters static pressure loss vs. cfm curve. Pretty significant increases in cfm can cause relatively small changes in pressure loss and vice/versa.

http://www.camfilfarr.com/files/prod...solute%20XH%20(high%20capacity).pdf

harddrivin1le

quote:
--------------------------------------------------------------------------------
Originally posted by Skeedatl
Faster moving air has less static pressure than slow moving air
--------------------------------------------------------------------------------

So

1) Increases in HP come from increases in Static Pressue

2) Faster moving air has less static pressure (meaning that slower moving air has more).

And we all know that air scoops SLOW the air.

Thanks - you just explained how air that is slowed creates more HP.

Skeedatl

Huh?

Skeedatl

Slower moving than what genius?

This is the whole point. You are good at cutting and pasting but it's OBVIOUS you don't understand the concepts.



The whole concept of "ram air" is that faster air makes more power.

It doesn't.

Never has.

Never will.

Swat Dude

That didn't work. Go here and scroll down to the product bulletin for the XH.

http://www.camfilfarr.com/script/pro...ppic=top18.jpg

harddrivin1le

An air scoop moving @ speed in a ram air system slows the air; it acts as an "air brake."

That results in higher pressure (@ the intake manifold).

P1V1 = P2V2

THAT is where the added pressure is coming from.