Calculate Your HP From Head Air Flow



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These equations are for recreation only.
Not a substitude for actual testing.
The HP is based on flywheel HP, for rear wheel HP multiply the results
by your drive train percentage loss and subtract it from the result.
This calculator is based on Naturally Aspirated applications.

For a more accurate calculation try Larry Meaux's Pipe Max.
His program is excellent and will provide a lot of info.
Pipe Max

Estimate Horsepower from Head Airflow
 Enter Depression of Airflow in Inches of Water:
 (The pressure your heads were flowed at) 		   in/H2O
 Enter Head Air Flow in CFM:
 (for better results use total cfm including intake manifold) 		 
 Engine CID:  
 Select Type of Engine Work:  Typ Street/Strip Eng
 Typ Race Eng
 SuperStock
 ProStock/Comp
 Mountain Engines
 Enter Number of cylinders:  
Input Head CFM, CID, and Test Pressure Please

These calculations are for port work with no 'choke'.
"Choke" is defined as the intake port with flow, but not
adequate cross sectional area to provide real intake
flow to fill the cylinders.
To figure your 'choke' - Choke Calc