Estimating flywheel horsepower at a known rpm – Calculated Industries 8703 User Manual
Page 45
H
OT
R
OD
C
ALC
™ — 43
you with this if they have an air-flow meter), as well as your engine
displacement.
In this example, your 1968 Pontiac GTO has a Ram Air II 400 CID
engine and you want to calculate the engine’s VE at 7000 RPM
which is the RPM at your maximum speed. Your measured airflow
capacity at 7000 RPM is said to be 625-cfm.
KEYSTROKES DISPLAY
0.
1. Enter your RPM, engine displacement, and actual measured
airflow capacity at 7000 RPM :
RPM S 7000.
ENG S SIZE 400. CU IN
USER S CARB SIZE 625. CFM
2. Calculate your engine’s VE:
EFF% 77.143 VOL %
The calculated VE of your GTO, at 7000 RPM, is about 77%. This
value is just under 80%, which for many typical street applications
is on track.
Estimating Flywheel Horsepower at a Known RPM
If you know torque output at a specific RPM, you can calculate
horsepower at that same RPM.
In this example, your 400 CID engine produces 445 pounds-feet of
torque at 3800 RPM. Calculate flywheel horsepower for the same
RPM.
KEYSTROKES DISPLAY
0.
LB-FT S MSA 445.