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Old 02-17-2014, 10:40 AM   #10 (permalink)
elhigh
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Quote:
Originally Posted by Gealii View Post
Can you explain on this? <snip>
If heat is lost through the transfer of the metal, the pressure would still be there to spool the turbo. <snip>
Simple physics.

Check it out: Boyle's law - Wikipedia, the free encyclopedia ; also look up
Ideal gas law - Wikipedia, the free encyclopedia

Heat is pressure. If you have a container of fixed volume and it is at zero psig (that's gauge pressure, so it has normal atmospheric pressure inside it), if you add heat to the container you increase the pressure. Lose heat, lose pressure.

Allowing the exhaust manifold to leak heat is to allow it to leak energy. You want as much of that energy to impinge upon the power turbine as possible, to spin it up and drive the compressor turbine that much harder.

Heat loss is the enemy in heat engines.
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