Inflating Balloons With An Exhaust - How Much Air Does An Engine Consume?


Well this is a super cool experiment!

In this video, a Honda S2000 has 2 balloons attached the the exhaust to show how much air passes through the engine.

In order to calculate the amount of air an engine consumes at wide open throttle, a simple straight forward process is used. The engine is assumed to have a volumetric efficiency of 100%, which basically means at wide open throttle, the engine can completely fill the cylinder with atmospheric air.

The Honda S2000 in this video, has a 2.0L engine and a rev limiter of 9000 RPM. This is a four stroke engine, meaning that for every two crankshaft revolutions there will be one intake stroke for each cylinder. At the rev limiter at wide open throttle, the flow rate of air thorough the engine can be calculated as 2 liters, multiplied by 9000 RPM, divided by 2. This totals out to 9,000 liters per minute, or 9 cubic meters per minute.

This is part of the equation on determining how much air an engine consumes as well as looking at the rate at which the balloons inflate.