Ram air on a diesel?

[overdrivegear]

My setup is working great.  No water issues.

[8v-of-fury]

I too personally saw a huge gain over my stock intake on my 1.6 na.. When I switched to 3" abs to my passenger side highbeam spot.. Above 1500 in any gear there was noticeable improvement.

However I am agreeing that this is not a ram air.. It is a cold air intake. And it does well.

[R.O.R-2.0]

if you want ram air, bolt a turbo on, they ram as much air as they can into the cylinder.. lol..

[8v-of-fury]

The only true ram-air. Turbo-Ramming.

[R.O.R-2.0]

find me an actual ram air setup that even comes close to boost??

might make 1 psi? maybe?

[RadoTD]

Not my calculations, found from google search on a forum thread here

Doing the math, assuming no losses:

pressure increase = 1/2 density speed ^2

pressure of air at sea level at 70 F = 14.696 lb / in^2

density of air at sea level at 70 F = .074887 lbmass / ft ^3
1 slug = 32.174 lb sec^2 / ft
1 foot = 12 inches
density of air at sea level at 70 F = .000001346969 slug / in ^3

if speed is feet / sec

pressure increase = 1/2 .000001346969 (slug / in ^3) speed ^2 (ft^2/sec^2)
1 slug = 32.174 lb sec^2 / ft
pressure increase = 1/2 .000001346969 (lb sec^2 / (ft in ^3)) speed ^2 (ft^2/sec^2)
pressure increase = 1/2 .000001346969 (lb / in ^3) speed ^2 (ft)
1 foot = 12 inches
pressure increase = 1/2 .000001346969 12 (lb / in ^2) speed ^2
pressure increase = .00000808181 (lb / in ^2) speed ^2

1 kph = 0.621371192 mph = .9113444 ft / sec

at 100kph, pressure increase = 0.067123 lb / in^2, less than 1/2% increase

To check the math, I compared with an article on ram air:

150mph = 220 ft / sec, and pressure increase = 0.391160 (2.66% increase)
1 psi = 68.948 mb (millibar)
150mph, pressure increase = 26.97 mb

For a speed of 150 mph, the resulting maximum theoretical pressure would be about 27mb (approximately .4 psi).

http://www.sportrider.com/tech/146_9910_ram/index.html

So yeah.. uh.. his math says .07psi at 100km/h and an article from sportrider.com claimed .4psi at 150mph.
I'll assume those are both correct, which seem to go along with what someone earlier in this thread was saying.
Colder air, definitely. Ram air seems to be overrated though

[RadoTD]

Just because imperial units are dumb and overcomplicate everything!

Pressure = n/m^2 = 1/6895 psi
Density = kg/m^3 = 1.204 @ 20deg C @ sea level
Velocity = m/s = 3.6 km/h

For 100km/h
P = ρ/2 * V^2
P = .6020 * V^2
P = .6020 * 27.78^2
P(n/m^2) = 464.6
P(psi) = .06738psi

For 150mph (241.40km/h, 67.056m/s)
P = ρ/2 * V^2
P = .6020 * 67.06^2
P(n/m^2) = 2707
P(psi) = .3926psi

[R.O.R-2.0]

i would rather have like 15 psi, rather that 1/15th of a psi.. lol..

TURBO!!

[Baxter]

just saw this thread popped up again.
Thought I best dig out the pictures....

I loved this truck, it had 250k on the clock and went like Billy-O.
Engine was original, and it revved, oh did it rev!
The air box mod made a big difference.

[trav1856]

Also, one might be wise to observe that the size of the opening, or more accurately the surface area of the opening is directly proportional to the amount of air rammed in. Granted, you're going to have overflow per properties of fluid dynamics, and there will be a point of diminishing returns, however...the size of your "scoop" will dictate how much available air you have to ram into the intake. It will not be anywhere near turbo levels, but say if I were to place a 3ft wide x 3in high x 3in deep air scoop under my front bumper, I'll have significantly more air available, than say a 3in diam hole, and the pressures will be greater at speed. But as previous posters noted, it won't be significant, but by increasing the scoop surface area of the scoop in the prior example (3x3x3), would be significantly more beneficial than a 3" round hole.

[Baxter]

I'm no fluid dynamasist, however my mechanics logic says that throwing the tiny beak away, chopping it down where it's a larger diameter and connecting a larger diameter hose to somewhere up from the ground and forward facing is going to be a damn site better that the factory snorkel.
I'm not saying that you get "Ram Air", I'm saying that there was a big difference between the standard item and what I did.
 

[trav1856]

I'm no fluid dynamasist, however my mechanics logic says that throwing the tiny beak away, chopping it down where it's a larger diameter and connecting a larger diameter hose to somewhere up from the ground and forward facing is going to be a damn site better that the factory snorkel.
I'm not saying that you get "Ram Air", I'm saying that there was a big difference between the standard item and what I did.
 

Agreed