Quote:
Originally Posted by markweatherill
Every little helps, as they say. But to be of benefit, the air entering the intake must be going fast enough to compare with the rate at which the engine is sucking it in, I feel. And that must equate to 'rather fast' in terms of road speed, although I can't work it out in my head.
|
I agree. I approached this in simple terms of providing more air than the engine draws in.
- My engine is a 4.7 liter V8 which is 285 cubic inches. At 2200 RPM it draws in 313,500 cubic inches (2200 x 285/2).
- My scoop has a face area of 48 inches (4 inches tall x 12 inches wide)
- At 70 MPH the truck moves 73,920 lineal inches per minute (70/60*5280*12)
- 73920 (lineal inches) X 48 (opening of scoop) = 3,548,160 cubic inches
- 3,548,160 (volume of air the scoop gathers at 70 MPH) divided by 313,500 (volume engine consumes at 2200 RPM) = 11.3
Quote:
Originally Posted by mcrews
I was speaking in general.
But specifically, since your second post made me re-read your first......
:....The ram air intake scoop gathers and forces somewhere in the area of 11 times more air than the engine can ingest at 70 MPH.
|
Quote:
Originally Posted by mcrews
help me with this sentence.
1. a-b-a. how much air can the engine igest?
|
I calculated the air consumption by taking the cubic inches (285) and multiplying it against the RPM's (2200) at 70 MPH and dividing by 2 since each piston only draws air every two rotations of the crank. This gave me 313,500 cubic inches.
Quote:
Originally Posted by mcrews
2. does it matter past the MAF/ECU
|
I do not think that it does. I am not actually pushing 3,548,160 inches of air into the engine - what I am doing is overcoming an intake restriction and keeping pressure in the air box/intake tube/intake plenum. With the first generation Tundra there is a flow restriction in the fender well where the stock air box draws its air from. By doing this I eliminated that restriction.
Quote:
Originally Posted by mcrews
3.how much air prior the this supercalafradulist scope was installed.
|
Under perfect conditions the engine would have only been capable of drawing 313,500 cubic inches of air per minute - but as I explained above it was not possible to operate at 100% efficiency due to the restrictions in the fender.