Mr. Softee

I have been told two ways to determine your lbs per air on the x axis.

Thisis from hondavision:

R x D x 0.5 x V x B
---------------------
1728

R = Max rpm the engine spins up to
D = Engine displacement in cubic inches
V = Natural volumetric efficiency of the motor
B = Absolute pressure ratio (Atmos + boost)

So...

An engine that maxes out at 8000 rpm, has a displacement of 110 cubic inches, with an inclination for 85% VE and running 7 psi of boost would be calculated like this...

7 psi = 7 + 14.1 = 21.1 / 14.7 = 1.48 pressure ratio

8000 x 110 x 0.5 x .85 x 1.48 / 1728 = 320 cfm

1 lb. of air = 14.285 cfm

Therefore, 320 cfm = 22.4 lbs.


Theyalso had another formula that someone pointed out as wrong...

is this the right way? also is .85 the natural volumetric efficiency for a b18b / b18c1? It this the same thing as the ratio of whp to motor hp?