king_johnthegreat

I never said thermal expansion; I said thermal energy. Heat is the contributing factor, not gaseous expansion. I do have the book; as well many other books. It makes mention of thermal energy and its contribution to enhanced turbine efficiency. Apart from the heat issue in the turbine side, the compressor side of the turbo does not suffer from heat soaking all that much. An intercooler is the key to pulling the added heat of compression out of the charge air, as is using a cold air intake to pull in the coolest air possible, anyhow. The air in the compressor side is there only long enough to absorb a small amount of heat from the surrounding surface; the heat it does possess is a function of the air molecules friction with one another due to the great amount of work performed on it. These are all very elementary physics and thermodynamics concepts that any other engineer could validate. Added heat on the turbine wheel means added work on the turbine wheel. The more work put on the turbine, the more work performed by the compressor; period. The torch on the undriven turbo is just plain out of left field. Try driving it with a given volume of gas with given specific gravity, then do the same thing with the same turbo, but with the gas at 400 degrees higher than previously. Nitrous doesn't just do a great job of spooling big turbos because of the added combustion pressures, but also (more so) because of the added combustion temps.
John

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Wood/Anderson Racing Development: j.anderson@wardev.com