# How much air does a car engine need? 300-900hp range? ?

At idle through full throttle acceleration how much air roughly would the engine consume?

How much air do turbos pump out?

And how would that measurement convert into air output from an a/c?

Update:

Okay update. I want to design a freezing cold a/c system to push cold air directly into the intake of the engine.  I was wondering exactly how much volume of air this compressor would need to cool in order to keep below 50 degrees Fahrenheit intake air. So my car would breathe cold weather all the time for hp gain.

The engine is a v8 4.6 4valve with 300hp

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• M.
Lv 7
1 month ago

It would be related to the engine displacement (cubic inches or liters), not the horsepower.

Every two crankshaft revolutions, the normally aspirated engine would ingest its displacement value in air (theoretically).

Forced induction systems (supercharging, turbocharging) would cram several hundred percent more air into the engine.

Relate that to the crankshaft RPM as the engine is running.

Carburetors have flow ratings, usually CFM (cubic feet per minute) which can be converted to LPM (liters per minute).

1728 cubic inches in 1 cubic foot.

28.31 liters in 1 cubic foot.

"And how would that measurement convert into air output from an a/c?"

You would be very surprised how much air goes into an engine every minute, compared to the tiny flow rate of an air conditioner.  It may mess up your fantastic idea.

-Engine overhaul mechanic and general automotive mechanic since 1972

• Ryker1 month agoReport

At this point, i have to ask. Why not a methanol injection system? I'm betting it would be way more effective at cooling intake charge.

• not at all in my opinion

• 1 month ago

To get 300 HP it is going to require burning 2756 cm/minute of fuel. Air is consumed at about a 12/1 ratio. Which means that it will take about 34,000 cm/minute of air for a clean burn. To make 900 HP would take three times as much. All you have to do is convert those figures (adjusting normal atmospheric to what ever temperature and pressure the design is) to compute the size of as AC needed to get the desired drop at the flow rate dictated.

• 1 month ago

Someone that asks "how much air does a car engine need?" is going to design a "freezing cold a/c system".

Yeah right.  And I'm going to design a spaceship and fly to Mars.

• G1 month agoReport

Elon musk is this you?? I'm a huge fan!!!

• 1 month ago

Let's just use the old 350 CID or 5.7 liter eight cylinder engine as an example. Each revolution the engine makes you would consume one cylinder of air fuel mix or a portion of 5.7 liters or a portion of 350 cubic inches. Each cylinder will suck in 1/8th of the total engine displacement. I believe it's one revolution per piston cycle on a four stroke engine. Intake, compression, ignition, exhaust strokes. Still early in the morning for me so my math might be off. Ha-ha!

• M.
Lv 7
1 month agoReport

A 4-cycle engine makes TWO crankshaft revolutions for one complete event: intake, compression, power, exhaust.

A 2-cycle engine would have an intake/exhaust cycle for ONE crankshaft revolution.

• Anonymous
1 month ago

This will get you started.

• Anonymous
1 month ago

A car with a gas engine traveling at a 10 km per liter consumption rate would need about 16 cubic meters of air for 10 kilometers traveled.

• 1 month ago

Depends on the engine. is it a four cylinder? 454 big block? A simple equation for finding flow rate is engine displacement times rpm/2. But this is assuming that each cylinder is filled with normal atmospheric pressure. Trying to find air flow through the throttle range and with a turbo would be a bit more challenging. Your best bet would be to use an exhaust flow meter of some sort.

• Ryker1 month agoReport

Hp has nothing to do with engine air flow rate. It deals with engine displacement, rpm, and the air pressure entering the engine, with the cylinder at bdc on the intake stroke.

• 1 month ago

You are going about this all wrong. The engine has a fixed displacement, often stated in liters. Take that. There is a power curve showing HP and torque per RPM. Use that and your engine displacement to calculate how much the engine will breathe. 300 to 900 HP is a ridiculous range. What are you working on? Let's start with that.

• G1 month agoReport

Okay update. I want to design a freezing cold a/c system to push cold air directly into the intake of the engine. I was wondering exactly how much volume of air this compressor would need to cool in order to keep below 50 degrees Fahrenheit intake air.

The engine is a v8 4.6 4valve with 300hp