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Calculating power of a Turbocharger

  1. Jan 23, 2010 #1
    Hi. My question is about the turbocharger itself and not about the resulting power increase from the added air in the combustion chamber.

    Can you calculate the power of a turbo if you have the change in pressure (atmospheric VS. Intake Manifold), and the change in temperature (outside air to intake manifold temp).?

    For example, you know the outside temperature is 25 C, the temperature after compression is 120 C. The initial pressure is atmospheric 14.7Psi, and after compression it is 24.7Psi. Volume is constant. Is there a way to find the power of the turbo if it is able to deliver this pressure change at a constant rate?

    I'm just looking for a ballpark number, no need to be exact.
  2. jcsd
  3. Jan 24, 2010 #2
    I'm sure there's a way to do it although I'm not in a position to figure it out right now, but, are you sure the volume is constant...during compression?
  4. Jan 24, 2010 #3
    I'm guessing the system would be the air intake side of the engine, so volume should remain the same throughout. I don't think the outside volume should be part of the system.
  5. Jan 25, 2010 #4
    Every revolution of a 4 stroke engine, it displaces half of it's displacement. So, a 2L engine moves 1L of air every revolution.

    Say you're boosting 15psi at 5000rpm, that's 83L of air at 15psi every second.

    I don't know the equation off hand, but however many joules of energy are stored in 83L of air at 15psi above atmospheric should approximately be the wattage the turbo is putting out. It'll probably be some stupid high number around 50kW; Those things pump some serious amounts of air.
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