How to Install A Turbocharger

Turbocharger Installation Guide Part 1: Mass flow calculation

This is the first part of article series related to turbocharger installation. You should know some basic calculations before you begin installing a turbocharger. Then you can move on to install the turbo by yourself or hire someone who is qualified to do the job.

Mass flow rate calculation

Mass Flow Rate (MFR) is the mass of air flowing through a compressor or engine for a specific period, expressed in units of lb / min (pounds per minute) or kg / min (kg / minute). This air mass flow can be measured accurately using a mass flow meter. But in many cases, estimated calculation is enough to determine the appropriate type of turbo.

Some people prefer to measure the flow of air volume (Volumetric Flow Rate – VFR), which is measured in Cubic Feet per Minute (CFM or ft3/min) or in SI units is expressed in Cubic Meters per Minute (CMM – m3 / min) instead of MFR. The volumetric flow rate can be converted into a mass flow rate by multiplying the density of air, which at standard atmospheric conditions (at sea level), the value of air density is 0.076 kg/m3 lb/ft3 or 1:22.

Then how to calculate the amount of air flow rate that is needed to achieve the expected performance?  The general calculation for a gasoline engine is that for each air flow as much as 1 lb/min (0.454 kg /min) would produce power (measured at the flywheel) of 9.5 to 10.05 HP (an average of 10 HP). This is the estimated average. So if you have a small, let’s say 1400cc engine, that is expected to produce 140 HP, then it will require air flow between 13.3 to 14.7 lb/min (6.0 to 6.7 kg/min).

Next article: How to calculate turbocharger boost pressure.


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