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Originally Posted by freebeard
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*I attempted an energy balance for the Turbina, and nothing I could do would reconcile the discrepancy between the reported values and physics.
*The car was tested only as a 1/5th-scale model in the wind tunnel.
* From Hucho's 2nd-edition, we find that the 1/5th-scale Schlorwagen model drag coefficient was 69% lower than it's actual 1:1-scale results ( Cd 0.11 vs Cd 0.186 ).
* Had the Turbina demonstrated a similar discrepancy, we might be looking at something in the neighborhood of Cd 0.2367, instead of 0.14.
* Even when discounted to the higher Cd, terminal velocity power absorption is only 135-horsepower at an assumed, drag-limited top-speed, compared to an available 288-hp at the traction interface.
* I located five cars with fineness-ratios similar to Turbina, which produced an aggregate average Cd 0.1661, at within 0.4% fineness-ratio agreement.
* We're cautioned to view 'early' wind tunnel quanta with a bit of skepticism. This certainly qualifies.