Inputs and Outputs for TURBOFLO.EXE











For a more detailed explanation, please see TURBOFLO.TXT











By John Estill





   BuickV6@aol.com











Inputs:





1) Ambient (or outside air) temperature - self explanatory.











2) Vacuum at turbo suction - the vacuum, in inches of mercury, at the 





   turbo suction bell.  Example: 1.5 in Hg (which equals -0.5 psig, or





   14.2 psia)











3) Turbo discharge pressure - the actual pressure, in psi(gauge), at the 





   discharge - NOT the boost pressure in the manifold.  There is some pressure 





   drop from the discharge to the manifold, so this will be at least a couple 





   of pounds higher than the manifold pressure as measured by a boost gauge.











4) Intake manifold pressure - the actual pressure, in psig, in the intake 





   manifold.  This is the pressure measured by the boost gauge.











5) Engine speed, rpm - the rpm for which you wish to calculate the air flow.











6) Engine displacement - in cubic inches











7) Engine volumetric efficiency - the percentage that measures how well the 





   cylinders get filled with air.  If you have 17 psi boost and the cylinder





   pressure when the intake valve closes is 17 psi, you have done a perfect





   job of filling the cylinder and the effiency is 100.  If it is less than 





   17 psi, then the amount you got/17 is the effiency.  For a stock street car,





   use maybe 85(?).  With intake porting, head work, spacers, etc... this





   number gets higher.  A tuned race engine with the proper runner length and





   size can go over 100 at certain rpms.











8) Turbo compression efficiency - the percentage efficiency from the compressor





   map.  The maximum efficiency for any turbo will be 80.  More commonly the 





   maximum efficiency will be about 73 to 75.  As you move away from the 





   point of maximum efficiency it will drop; the farther away you get the less





   the efficiency.  If you have no idea use 65.











9) Is the car intercooled? Y or N.  If No, the manifold air temperature will 





   be the same as the turbo discharge temperature.  If Yes, make an assumption 





   for the intercooler outlet temperature.  With a stock intercooler I am





   guessing that the outlet temperature will be about 40 to 50 degrees above





   the outside air temperature.  With a front mount it will probably be closer





   to 15 to 20 degrees above the outside air temperature.











Outputs:





1) Pressure at turbo inlet, turbo outlet, intake manifold (all of which you





   specified), in psi(gauge).











2) Temperature at turbo inlet, turbo outlet, and intake manifold.  The inlet





   you specified, the outlet is calculated based on the compression and the





   inlet temperature, and the intake was either specified or is the same as





   the outlet, depending on whether the car is intercooled.











3) The air density, in pounds per cubic foot, of the air at the turbo inlet,





    turbo outlet, and intake manifold.











4) The actual volumetric flow, in cubic feet per minute, at the turbo inlet,





   turbo outlet, and intake manifold.











5) Air flow, lbs/min - The mass of air moving through the intake system.  The





   air to each cylinder is this number divided by 6.











6) Turbo compression ratio - the turbo discharge absolute pressure divided by 





   the turbo suction absolute pressure.











7) Turbo compression efficiency - as you specified.











8) Corrected air flow - the "corrected" mass airflow for use with the 





   compressor curves in the Turbonetics catalog.











9) Displacement, rpm, and volumetric efficiency - as you specified.