The equation for that graph was provided back on page one of the thread so the answer was here the whole time. The OP just had "wiki induced brain freeze" which is a relatively new disease. Didn't exist when I was a kid.

Your just not getting it

SHOW ME BOOST! On a car, not a plane, boat, ship, jet, ufo, mosquito after taco night, a bad night of explosive diarrhea but a car travelling at 100mph, or even 200mph, with ram air induction showing BOOST.

Pretty simple request.

RE:

I think YOU'RE (not your) not getting it.

You want boost?

Look inside the pitot tube. There is your boost. Even if you stick one on a car.

ANY increase in pressure is technically boost.
Raising a vacuum 1" closer to atmospheric pressure is boost.

If you want to see 14.8 psi inside an engine on a 14.7 ambient day without going stupid fast then you're going to need mechanical assistance.

There.

Are you happy?

See I didn't have to show anything.

I make a real concerted effort to not let these things go personal.

But The Pontiac/Chevrolet tidbit above has me raising my eyebrows, again, because I have never heard that explanation before, there is no obvious explanation for his conclusion, no quoted source/reference, the author who is connecting the dots, and the author's track record here on this thread, already connecting unrelated dots. Just my opinion before it gets written in stone.

Sport440
{Why would ram air boost stop at 14.7???} Answer, It doesn't.

It increases from whatever the starting atmospheric pressure is currently at.



BUT, It WILL, still be Boost, A Increase in PSI with a Working Ram air Effect. ANY Increase is BOOST by definition.


[/quote]



Sport440,
Okay Now you changed your original question,

From,...{ The Myth of ram air...does it WORK in cars/trucks}

TO;{{ Boost is defined as 14.7psi + xx}}


Ram air boost can start at any MPH from zero and increase from there. There have been formulas and charts posted to prove that.

It takes 70 millibars to achieve 1 psi of boost.

Ram air systems, for most of us will be below this level, but still capable of .50 psi around 150 MPH .25 psi around 100 MPH .125 around 80 MPH

So pick your MPH from any of the above for your {Boost is defined as 14.7psi + xx} and add that. 14.7 + .25/100 MPH = BOOST

Ram air is{ No myth}. CONFIRMED

Probably the best apples to apples comparison offered. This car is a 1994 SLP firehawk (Ed Hamberger's company.) The only changes done between this car and the 1994 V8 firebird is the "ram air" induction... The standard V8 firebird made a rated 275 crank hp the firehawk made a rated 300 crank hp. Same heads,cam, exhaust (the optional exhaust added 15more) same throttle body. Ect. There was a tune change required and a map location change required but nothing crazy because the car still had to pass cal emissions... Basically, Just the hood which is sealed to and feeds directly into the throttle body. Now you could say "oh its marketing" but time slips don't lie. The std V8 FB was no match for the same year Vette in 0-60 or 1/4 mile...But the Firehawk easily beat the Vette which btw also used the same LT1 engine with a different cam. So, Ram air > camshaft in power gain. Yes there's suspension changes, and vette sized wheels and tires. No gear changes. Please explain this any other way.

R70 - you answered yourself - they tuned it, put a lighter bonnet on, changed to possibly? lighter wheels, better suspension and better exhaust - how much came from ram air - un-answered. The firehawk was still 200lbs heavier than a c4 though, go figure on the 1/4 times - obviously a better thought out/engineered package.

Not going to knock ram air though, an 1/8th of a psi is an 1/8th of a psi, as stated above the temp difference would be where its at for major performance changes vs under bonnet air

Arguably you would be better off using the cowl air routed to behind the front wheels to help reduce the aero CD

You got your answer in the first few posts. It's about fresh or cold air. A scoop that isolates the intake to the air outside the engine compartment will get you colder, denser air. A scoop above the boundary area is going to get you more cold, dense air no matter what speed you're traveling. I've been told this is good. Ram Air is a name Pontiac concocted, as did dodge with Ramcharger. It all works to get you fresh air, which is exactly why Chrysler referred to N96 as the... Fresh Air package and not the Forced Air package. The last four pages of forced air debate is off topic. Ram air works, my friend, and lucky for you, the 1969 1/2 A12 cars have the best production scoops ever produced. Go now. Celebrate.

Everyone is going to have an opinion ranging from their seat of the pants feel, to the highly educated and scientific, so I will skip an opinion and give my personal "i did this" report. For years on my Dart drag car I ran just a flat hood with with a 14" x 3" air filter, then after a time I decided to try a dual ram air set up just to see if it would net anything. I used flex dryer duct from the air cleaner down next to the radiator and attached to the underside of the bumper, just about a foot off the ground. After running that set up for about a year and having torn it off a couple of times loading it onto my trailer I decided it was time to lose that and go with a hood scoop. Before to ditched the ram air set up completely, I wanted to test all 3 set ups to see the difference between them. Keep in mind that the air cleaner used with the ram air dual inlet had no air filter, I just used a 3" wide piece of sheet metal shaped to the same circumference as the filter, cut 2 oval shaped holes in it for the snorkel fittings and put a lid on it. I didn't want the filter to be a restriction. Here are the results for the test, all on the same day, all within an hour of each other in like conditions...
Run 1, 14" x 3" air cleaner with filter, no ram air-11.57 ET
Run 2, 14" x 3" air cleaner assy without filter with dual inlet ram air-11.42 ET
Run 3, ram air assy removed including filter assy, carb sealed to underside of hood with foam, with the scoop in my sig pic-11.27 ET.
Point of interest and probably disagreement, there are those that will say the gain from run 1 to run 2 (adding ram air) was only from introducing cooler air, but on the hottest of days, with the ram air inlet only about 12" off the pavement, that air isn't going to be to cool, not as cool as the underhood air temp once the car was making speed, and the car on any given day was always about a tenth and a half quicker with the ram air. I do believe its a combination of both, and the fact that I had to jet up the carb 2 jet sizes tells me that more air IS being forced into the engine. A LOT of air moves into and out of the engine compartment through the grill opening at speed. I believe the even bigger pick up with the sealed hood scoop was a combination of a shorter, more direct path to the carb and the air being forced downward, and a cooler charge of air given it was coming in through a much higher opening, never coming in contact with the underhood heat at any point. Whichever you believe is the correct answer, the FACT is, it works!