Ram Air
 

I am going to ram air my car and would it be better to get equal-length headers with this being a forced induction or should i stick with the unequal

Thanks

Ram Air, at least in your case, will not be forced induction. You will never be able to drive fast enough to have the incoming air move at a faster rate then the vacuum that is sucking it in. Don't kid yourself. A better name for it is cold air induction, because that is the only benefit you will get. Header length makes no difference based on a cold air induction set-up.

Take care,
~Chris

OH some one had told me that ram air was a forced induction and that equal length headers were better with the ram air kit.

just a little peice of info i thought I'd share... I've got a 72 olds and one of the options for the car was a RAM air hood... but the actual option was called the OAI hood ... outside air induction... so even the factory didnt call it RAM air... but if nothing else, it looks pretty...
-as

I dont know about forced induction or not or whatever cuz Im not very smart when it comes to cars...but I will Say I recently bought a March Ram Air Kit and installed it...it increased my gas mileage and not necisserly made MORE power but above about 50 MPH it incresed throttle responce remakably...before I could be running 60 and give it about 3/4 throttle and it would slowly crawl up there...but after...I give it 3/4 throttle at 60 and WOW....If its a march kit you are talking about buying...I would say go for it I really like mine and even purchased it used (From FiveOhPatrol which might I add is a VERY good person to buy from...fast friendly and honest)...and if you dont like it...you can always sell it...:D

How exactly does Ram Air then work? Like how would the system suck in the air faster then your going? Just wondering..... The shaker hoods on the ol' Mach 1's weren't really Ram Air right? They were the same thing correct?

§am.

Ram Air is a marketing tool. It's a catchy name that has nothing to do with it's function. They can increase responsiveness and power, but not because of a Ram Air effect. They allow colder, denser air to be sucked into the engine, which helps, but they also reduce the bends and turns in the path that the air has to take on it's way in.

It's easy to sell the idea of Ram Air to the average Joe, because odds are he's never put his hand over a carburetor on an engine turning 3000 rpms. Besides, it sounds neat. But, if you want to see for yourself, just attach a vacuum/boost gauge to any n/a engined vehicle, and try to get it to go from vacuum to boost.

Ram-Air is nothing more than cold air induction with a less restrictive path for the air to follow, which is a good thing. But it's not forced induction.

Take care,
~Chris

4cyl_Of_Fury, glad you are happy with the kit

and by the way, I had no idea that you were a member on MW :D

yes yes I am...one of the less active ones but yes a member...all of the selling and buying was done through my bro pony_power_90....

You guys aren't gonna start singing "It's a small world", are you?

;) :D

Take care,
~Chris

Its a small world after all. Just kiddin. And I do recommend the kit. I havent driven a 5.0 street car in quite some time. I drove Adams car before and after the install and I could tell the difference above 50mph like he said

Bradley

pkrwud is both right and he is wrong.

Most ram air systems are only cold air inductors. He is completely right about that. That is because the incoming fresh air charge has opportunities to escape and reduce their pressure effect.

He is wrong because all the bug scoop ram air systems we used on engines from the 50's on up show a very demonstateable 10 horsepower increase on the dyno both at the flywheel and at the rear wheels.

Running cold intake alone does not build the same horsepower as ram air.

On a track like Daytona, where you can reach 200 mph on the high banked oval, ram air was an essential and critical element to make the horsepower necessary to be competitive.

pkrwud is correct to say that ram air is not forced induction. It does not show boost. However it does increase the air's density and with the intake charge being carefully tuned, you do see extra cylinder filling at speed with a ram air system. That is what builds the extra 10 horsepower.

Hope this helps a little.

I like ram air. Works great on the fords with the shaker hood scoops. I am trying to finish a cold air induction - ram air system on my 358. I just keep getting stalled by other more pressing issues.

Pkrwud has not said this yet, so I will offer you this tidbit now. When it comes to a carburetor, you need smooth and vertical air flow through the venturi's to get optimum atomization. So I like to use K&N filters with K&N's new X stream top. This smooths the air flow and gets the best from my Holley.

For a fuel injected engine, running a cold air intake with a ram face may not give you any extra horsepower, because your computer is triggering your injectors based upon mas air flow. That is why I like speed density fuel injection for race engines, cause I can "tune" the engine with the fuel injection like I can "tune" an engine with a carburetor. So a ram air speed density system might build the extra 10 horsepower. The MAS for some reason will NOT.

Can anyone fill me in on why MAS does not respond to ram air? I really have never figured this out.

How the H3LL can you increase HP with a ram air effect on a stationary dyno.

LMAO:o

shop fan? :D

By using a wind tunnel based air inlet....

how do I describe this.....

By utilizing a miniture wind tunnel, you can create an air inlet subsystem to alter the air temperature, air volume, and air density. This is all computer calibrated since the 80's.

You hook the output of the inlet subsystem to the carb or air intake on a fuelie. This allows the dyno to see specific effects of track temperature, air density, or ram air volume effect on any engine we test.

You can use this to test the effects of a K&N Stub stack, or an air filter arrangement, or a ram air system.

These were originally created to dyno aircraft engines at different altitudes, bariometric pressures, and the like....

Need I say more.......

You beat me to it.

Take care,
~Chris

pkrwud,

I wish you could have seen the stretched Ford "fatbody" we built with a rolls royce Merlin engine. 2,000 horsepower and a world record at Bonneville.

I got to help with the bodywork and under body pan to cut wind resistance and improve downforce at 250 mph.

I did not get to wrench on the aircraft engine, I was only allowed to stand and admire it.

This was a good thing for sure, because I can break anything ever built. Just ask anyone who knows me well. I break stuff all the time.

On a historical note, these same engines were used on P 51 Mustangs and British Spitfire fighters during WWII. They were the only prop aircraft that could break the sound barrier during a dive. P 47's did this with the 2,000 hp Pratt & Whitney rotary piston engines, but they had to be nose to the deck, and you did not always get a chance to pull out of a dive like this when you lost all aerodynamic lift.

Have a great weekend.

When we set the worlds record for the fastest motorcycle, we used two hogged out V-Twin Harley engines. That was a badd-a$s streamliner!

I will have a great weekend, thank you, and I hope yours is teriffic as well!

:)

Take care,
~Chris

Hey, back to the header question--who cares about rolls royce merlin engines anyhow......

For some reason I could NEVER get a proper explanation on, an equal length header either short or long develops more hp and torque than unequal length headers.

I really like the Flow Tech headers that take the one out of phase cylinder on each head's bank, and put that tube under the collector for the three in phase primary tubes. This improves the scavanging of that out of phase cylinder.

I would think the ram air would help ANY engine. Ford showed a 10 hp increase on the 351 C 2V and 4V heads with the shaker hood. The Cleveland ran really stupid cast iron headers that were power KILLERS. We always ran long length equal tube headers on these cars in order to regain some of the low end torque lost from those HUGE a s s ports. Even the 2V Cleveland had HUGE a s s ports, but at least they could squeel the tires at will.

So go ram air now and enjoy the extra power. Change to a better header when it is convenient to do so.

Adding an H pipe might add back any horsepower lost to your unequal length headers if you have a basic warmed over engine.

Have the shop build you off-road pipes so you can pull the catalytic converter off when you race. Make sure you put some antiseize on these bypass pipe bolts so when you need to remount the cat(s) it will be easier to do.

Removing the cats and adding an H pipe might be good for 15 hp or more at your rear wheels, and the cost is negligable.

I think that is the first time that phrase has ever been said by anyone:D

I have a cervini stormin norman "ram air" hood. I love it, I love the looks and I love the sound. Have noticed no extra power, but I love it! :)

(the headlight, and foglight covers are gone now.)

http://www.joe4speed.com/frontstang.jpg

I have a cervini stormin norman "ram air" hood. I love it, I love the looks and I love the sound. Have noticed no extra power, but I love it!


Joe4speed what does it sound like refering to the sound you like

i thought "ram air" only works as it says at really high speeds like 190+(roughly) mph. is that true?

D a m n,

here I go again gettin techie on ya'll, and then out will come those jim bashers sayin I'm a know it all.

I don't know it all. I learn new stuff every day. I break everything I have ever raced. I build stuff at the edge of the envelope and I drive it like it will last forever....

Ram air.

Actually, hold you hand out the window of your car as you drive down the road. For every 17 mile per hour the temperature of the air compresses against your hand and drops 5 degrees f.

That is why a jet traveling 475 mph has an outside temperature of -30 degrees f to -60 degrees f. (the friction of the air warms the aluminum skin, but the compressed air cools it down and the temps above are what remains.

So at 17 mph your engine will love having denser, compressed, cool air. At 70 mph the air is really streaming in. At 120 when you go through the speed trap of your drag strip, the air is super cold, super dense, and tightly compacted. This is why ram air is so effective. It is free horsepower, but remember you will need to rejet your carb or you will go leaner as you go faster. This is disastrous. A speed density EFI might want some recalibration. A MAS EFI will make the corrections as part of its normal function.

Hope this helps.

Now try to stand on top of your car while it goes 70 mph. The wind blast will make you slip and slide, at 100 mph you could not remain on the car without tether straps.

what i meant Jim was for actual "ram air" to be affective the most, high speeds is where it is more useful. correct me if am wrong know it all!:p

There will always be negative pressure, or a vacuum, between the carb and the "ram air". The ram air can not and will not exceed the amount of air the engine is asking for.

James, don't get confused, it's cold air induction, period. Same rules apply.

:)

Air flow over an object will exchang heat more quickly the faster it moves, know as wind chill factor, but the temp of the air does not change, or its density. I'm also sure the air is cold at 10000 feet, at any speed.

BUT, The point is, non under hood air is better than under hood air. The chevy cowl hood, is a good example this, not a pressure thing, just cool uside air.

Exactly. Very well put.

Take care,
~Chris

not even at 240 mph? seriously, it never changes it state from cold air to somewhat of forced induction at a REALLY high speed? i use 240 cause the McClaren F1 can do that.

Better yet, the Z06 Vette. rated at 405(right?:confused:) can do 200 mph, so if i had a ram air, you mean to tell me at 200 MPH that engine is sucking the air in rather the air forcing itself in? :confused:

by the Ideal Gas Law--> Pressure*volume=density*constant*Temp.

I dont see velocity in there, so the density does not change.

By definition pressure= area*velocity

so area*velocity*volume=density*constant*temp

However everyone on here is correct when they say that even at 200 miles an hours the engine is still sucking air in rather than having it forced in.

what make you think this is true?

pressure's units are: force pre unit area (ie Newtons/meter^2)

how does this equal (m^2) * m/sec ???
or for you english units people: lbs/inch^2 does NOT equal
(in^2)*ft/sec

The sound is cool... I can't really explain it... It makes a low growl when you first floor it, coming from the ram air holes in the hood. The deep intake noise... I can't explain it!!! LOL

I agree with you Joe, I have had hood scoops on 4 of my last 10 cars, and I have a functional cold air kit on my truck that I have affectionately called Ram Air.

James-
Does the air that enters a jet engine ever pushed in faster than it's sucked in? Even at 1500 mph? No. If it was, the jet would stop accelerating. Unless of course it's got the engines killed, and is in freefall.

In an automotive application, the more direct the source is, the better, but it will never be forced. It's nothing more than a cool sounding name for cold air induction.

Kinda like blower vs. supercharger. lol

Take care,
~Chris

fiveohpatrol wins my first award for finding one of my flaws.

Obviously the air does not become denser as it compresses--only colder. However the air fuel charge IS a much denser "charge". You get extra cylinder pressure when the denser air/fuel mixture heats up under the compression stroke. This is where the extra horsepower of ram air is created.

No......The air being pulled through your manifold is over 500 mph. You would have to exceed mach 1 in order to pressurize the carburetor or FI system. Do you see this?????

FiveOhPatrol! Awesome!!! Good catch, I did not expect anyone to call me on this one. This is like post grad level internal combustion engineering!!!!

YOU ROCK!

By the way, some gases will become more dense as they pressurize and will change states from gas to liquid. Liquid Hydrogen, Nitrogen, and Oxygen are several gasses that do become "dense" as a function of their compression. In physics we like to say it is not dense but just a change of state from liquid to gas and back, but a "chaos" theory mathemetician would dispute the physics instructor from now till the end of time.....

I guess I fall somewhere between the two pencil necks. Gotta love those of us who refuse to pick sides......



MOST EXCELLENT.

you are an odd odd man :)

ok I was wrong with my first equation but let me correct myself. Let me start with this

I'm not understanding this because if you compress air you make it more dense. Also if you compress a gas it heats up, it doesn't cool down. Think about a nitrous bottle. When you shoot the juice you decompress the bottle by letting liquid nitrogen escape. This is what makes the bottle so cold.

Now as for the pressure being dictated by velocity, I was originally wrong with my equation. If you look at the equation of continuity and bernoulli's equation, you get two things, a1v1=a1v1 and that work is equal to the difference of two pressures time the volume of liquid(air) to pass over a section. putting these two equations together and substituting back in, ,you get pressure change*volume=.5*mass*velocity at point 2 squared + .5*mass*velocity at point 1 squared. This means that velocity and pressure are related.

Think of it this way. You have a garden hose. You put your thumb over the end of the hose and the water squirts out faster. You decreased the area of the end of the hose and that made the water move faster. But in order for the water to move faster, you must increase the pressure. Thats why the more of the hose end you cover, the harder it is to keep your thumb over the hose. if you think im wrong doublecheck me in "Serway and Beichner's Physics for scientist and engineers" volume 1 fifth edition pages 470-472

and its not post grad engineering, its freshman physics.

basically your saying demand is higher than supply, right? i see what you are saying now. what happens if you put a venturi in the tract of the "ram air"(not the carb)? at 200 mph? i would be curious to know.

thanks Chris

There is an engine called a RAM JET engine which actually uses speed and the "ram air" effect. At speeds over mach one, around 700 mph, planes create a shockwave, basically waves of super-compressed air. The engine is designed to direct these shockwaves into the engine to produce forward thrust. At speeds of over mach 3, the "engine" itselft just gets in the way of the compressed air effect. So there are instances in which the air is actually pushed into an engine faster than being sucked in, but it was only really used in the "Blackbird", an air force recon plane. The only problem is this kind of engine is only effective at speeds greater than mach one, so a standard jet-turbine engine must be incorporated in to get the plane going at least that fast before the ramjet can take over... GO here for a more detailed description of how this works: http://www.grc.nasa.gov/WWW/K-12/airplane/ramth.html

Very interesting, I especially like the little enginesim java applet, here, switch to ramjet engine type:
http://www.grc.nasa.gov/WWW/K-12/airplane/ngnsim.html

Ramjets are very interesting, its kinda weird to realize that they can shut it down, and still accelerate:)

But not too many people have put a turbine engine into a street car:D

Agent_4573, are you an engineering student as well? If so, what school?

Yeah, I'm an engineering student, I go to the School of Engineering at Rutgers, the State University in New Jersey, New brunswick campus.

and to think...all this got started by one little question....and here we are discussing physics....and just me $.2...its still a good buy!:D

Rutgers. Wow. I used to live in Bound Brook.

It IS a small world afterall!

:)

Take care,
~Chris

DAMN YOU CHRIS!!!!!
 

You got that STUPID F'ING song in my head from Disneyland. I'm going to have that annoying song in my head for hours.

You're welcome.

:)

Thats awesome... now if only i was like 50 years older i may have grown up with you...


just kidding there chris... I know your not that old...

1989stanger, thank GOD that you didn't ask about heads, or even worse a cam :)
I think we are arguing about religeon and not focusing on GOD. (so to speak) Any way to ansewer your question, long tubes, and ram air will be the best route.
Fellas, I wish you all would help me with my big gear and tire question......Please.....Fast Mustang Please :)

Smarta$s.

Best be careful or I'll beat you with my cane!

:)

Take care,
~Chris