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Old 05-21-2010, 09:52 AM   #24 (permalink)
Aero Wannabe
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Originally Posted by autoteach View Post
Turbo engines do operate under different principles. The critical portions are the header/manifold up to the turbo, which people typically leave alone, and the pressure difference between either side of the exhaust turbine, which dictates lift on the blades, which effects rpm-boost-power, and so on. There are points of diminishing returns, where the bigger pipes net no increase in power.
So Autoteach, I read the Exhaust Theory 101 and I get the exhaust scavenging concept. But in a turbo car, does this mean that the whirring turbine blades eliminate the pulses at the turbo and therefore from that point on bigger is better, even for ecodriving? A 3" exhaust on a 1.9 TDI could increase mpg at light engine loads?
60 mpg hwy highest, 50+mpg lifetime
TDi=fast frugal fun

Originally Posted by freebeard View Post
The power needed to push an object through a fluid increases as the cube of the velocity. Mechanical friction increases as the square, so increasing speed requires progressively more power.
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