unstable Vic

iTrader: (6)

If you fart in the woods, [stinky air], would it make noise????????????????????????????????

Fast Toys Performance Parts

iTrader: (3)

A normally apirated street motor is not 100 % VE. That means, the motor does not inject the full displacement of air that it has the potential for. A race motor can actually meet or slightly exceed 100 % VE due to proper intake design. As stated, a ram air kit accomplishes the power increase through a few methods:

1. Increase VE (less restrictive intake path).
2. Lower intake temps
3. More timing because of lower intake temps per the IAT sensor

Just about all FTRA users will report better fuel economy with the ram air kit installed. In fact, Install University tested this premise in an article on their web site. The only way you are going to get an increase in fuel economy is if you can increase the efficiency of the motor. Thats what the ram air kit is doing for you.

You don't need to exceed atmostpheric pressure to achieve an increase in performace. Just getting the VE closer to 100 % will make more power and increase efficiency.

Here's a real world example:

Take a paper bag or a parachute and crumple it up. Under atmospheric pressure, it doesn't fill up with air. It stays crumpled. No put a large fan in front of either. The bag/chute inflates. The air wasn't compressed to fill the bag/chute.

Bottom line is the system works.. thats been proven over and over.

My two cents... no, I am not an engineer <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

<small>[ April 23, 2003, 01:41 PM: Message edited by: Fast Toys Performance Parts ]</small>

Jpr5690

iTrader: (13)

i was just thinking the orig statemnt said that you need a small opening with someething to slow air down to create static pressure right well compared to the air box the hood vents are a small opening and further thinking about it the air filter and ribs on the stock air lids slow the air down quite a bit so by ur own defnition would be the correct tool for creating static pressure out of dynamic pressure,since it does make a small opening with a large base right????

Stangklrws6

I say if you want to "ram air" into the motor throw a blower or a turbo on it.

I would think that the scoops on the ram air hoods really wouldn't be effect because of the aerodynamics of the car, the openings seem just a bit too small to beable to effectively work in creating thus said ram air effect

WS62GO

dead horse <img border="0" alt="[judgement]" title="" src="graemlins/gr_judge.gif" />

joecar

All theory aside (I'm not knocking thoery), common sense dictates that if you put a scoop into the air stream you'll get air flowing thru it at some velocity (i.e. helps the engine get air in);

Race cars use scoops to channel air thru the brakes for cooling, and our F-car radiators are cooled the same way;

The pressure may not be much (get a supercharger it you want lots of pressure), but the rammed air does have some velocity, and the air is cooler than inside the engine bay;

(...actually, if you look at our Ram Air scoops, they are smaller in front and get bigger further back... just as discussed in regards to static pressure and scoop shapes...);

And if you don't have a WS6, why are you complaining that Ram Air is just hype...?

<img border="0" alt="[driving]" title="" src="graemlins/gr_driving3.gif" />

SSpilot

Who ever wrote this spent way too much time looking up big words in the dictionary, the whole principle boils down to a "Venturi" effect. you would want the scoop to be bigger at the intake, as it narrows, the fluid (air) must travel faster becoming more effective. In laments terms, it gains more horse power, and the numbers don't lie

HiRiser

This is all really old news, but is fun to see it come around now and then. Mopar did big studies on this in the 60's and 70's and they <img border="0" title="" alt="[Cool]" src="gr_images/icons/cool.gif" /> are very well documented in the SAE publications of the period. May want to check out the local university engineering library to look for 69-70 SAE issues where it was all published.

RA is true and works as most of the replies have indicated. The big thing for the efficacy of RA is to stay off the boundary layer of the car, which unfortunatly Detroit usually does not do. A great example of an effective (read isolated from the boundary layer)RA is the 70 Challenger T/A hood scoop and of course the pro-stock scoops.

98PurpleT/A

iTrader: (16)

WHAT!! Santa Is Not Real

TS6

iTrader: (41)

You bumped a 7 year old thread for that gem of a post?

Retards....

Squirts11

iTrader: (14)

Considering it's his 6th post in 5 years, I suppose I'm not too surprised...

Siciliano15

iTrader: (7)

i just read the article about how ram air doesnt work and i have to disagree also. i went from having the slp lid with blackwing filter to getting the jaam ram air kit and removing all of the baffles in the hood and it made a huge difference at highway speeds. now punching it at 60mph in my a4 car the front end jumps up and it really takes off strong. before it was quick but it easily picked up some great initial torque and probably somewhere around 15-20hp at high speeds for me to be able to feel it that much.

chrs1313

iTrader: (24)

haha 7 year old thread...I will take my 2.7mph from my ram air...I am glad when people think it doesn't work ...

t56 that made me laugh...

Magic Man

It does work but the amount depends on the speed you are moving.

94Z28rag

iTrader: (10)

Are you sure it's not just colder air entering the engine? Sounds more plausible.

Just stirring the pot..........

HAZ-Matt

iTrader: (8)

I not only disagree with ram-air effect not existing at less than trans-sonic speeds, but also with the notions of gravity and electricity. Some egg-head scientists just made all that stuff up.

claytonisbob

iTrader: (1)

Holy bump Batman.

This argument is kinda silly. "Ram Air" is a made up word, which is never defined as "pressurized air" as far as I can tell. Colder, faster moving air isn't a bad thing, so to say scoops don't work is a farce.

"Ram Air" would have the same effect as a long intake runner that sticks outside the hood... Velocity caused by aerodynamic force and a long runner. Think Hilborn velocity stacks.

If I were to have a big *** cone (36" at the opening, 48 inches long) with a 4" hole at the small end, think of how fast the air would be moving out of the hole if the cone were traveling with the opening forward at 50mph. If it's any faster than 50mph, then I'd assume there would be a benefit to having something like this attached to a moving engine. Though the aerodynamic drag of such a device would probably be more power robbing than beneficial.

chrs1313

iTrader: (24)

actually the velocity would be the same coming out of the cone at the 4" end...air is basically incompressible at the speeds we travel at...I say basically because it does slightly compress...if I remember correctly without running numbers at 100mph it will be around .2psi...could be a hair less...

so actually if you really wanted ram air to pressurize something you would face the cone in the opposite direction with the small side facing the incoming air charge and the large funnel side facing the engine...

PV=nRT

P = pressure
V = velocity
n, r are constants in this example
T = temperature, also a constant in this example

so P1 x V1 = P2 x V2

they are inverses...for the pressure increase from P1 to P2 the velocity needs to decrease from V1 to V2 and this is achieved by having the funnel facing small side out large side in...

this is at alot higher speeds though

the reason we get some pressure with our ram airs is because we are taking that speed of 100 and making it basically zero...so it becomes a slight pressure...

since air is incompressible at these speeds pretend it is water cause air is a fluid too right?...so

how much water can flow out of a garden hose at 50psi...

now imagine that same 50 psi out of a fire hose...

in this situation the 50 psi is the speed the car is traveling...the hose sizes is the smallest part of any ram air system on your car...this is why I made my ram air the same width throughout...if I were to neck it down to 2" I might as well make the whole intake 2"...the larger the cross sectional area the better of the smallest portion...so why now make it huge like 10" x 10" that will supply more air than 5" x 5" right...well all we are accomplishing is having that next ready amount of air for the engine to take in on every stroke ( just so there is no vacuum caused by the engine, see link for more on this)...once you hit a certian point it is just excess air or intake if you will...what is that magical cross sectional area? well for each engine it will be different and it will take testing...in my case of the ram air I made I just made it as big as possible within the dimensional constraints...we can always use a little head room right?

didn't proofread this hope it makes some sense

here are some interesting links

https://ls1tech.com/forums/generation-iii-external-engine/924996-my-ram-air-vs-stock-setup-how-much-hp-dif-track-results-tom.html

https://ls1tech.com/forums/advanced-...ng-around.html

claytonisbob

iTrader: (1)

So I don't really understand. If air is not compressible at a car speed range (say 100mph), what is a high pressure area on the car (like at the base of the windshield) ? If the aerodynamics of a car causes high and low pressure areas, it's compressing air somewhere, is it not?

Same could be said for an airfoil, the only reason an airplane can fly is because of the high and low pressure areas created by the shape of a wing. And some airplanes can fly at very low speeds (think ultralights and crop dusters).

chrs1313

iTrader: (24)

key word ultralite...

not understanding doesn't make it false information...do some research...

yes those are high and low pressure zones on a car but don't think high means 5psi...at most maybe .2psi as stated earlier...air does compress but it is a vary small amount...

atm pressure at standard conditions is 14.7 psi so a pressure in a high zone at 100mph is 14.9...air only compressed to 98.6% of the volume it was...so basically incompressible at the speeds we travel...

the point is to reduce the vacumm in the intake and give a slight pressure which a ram air does...hense why the gains are seen...