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Posted: Oct 02, 2008 2:50 PM
by Nebraska_e28
turbodan wrote:
No matter which kind of supercharger you use and no matter how you do it, you can be sure that the same system with a turbocharger will be more efficient and make more power.
Why is that? Is exhaust scavenging a more efficient way of providing boost vs. a belt/pulley system drive off the crankshaft?
Posted: Oct 02, 2008 3:17 PM
by Shawn D.
Nebraska_e28 wrote:turbodan wrote:No matter which kind of supercharger you use and no matter how you do it, you can be sure that the same system with a turbocharger will be more efficient and make more power.
Why is that? Is exhaust scavenging a more efficient way of providing boost vs. a belt/pulley system drive off the crankshaft?
A turbosupercharger extracts waste energy from the exhaust to drive the compressor. A mechanical supercharger is 100% parasitic. It could be argued that the turbo is partially parasitic, but even then, it's still taking a good bit of waste energy and putting it back to use.
Posted: Oct 02, 2008 3:25 PM
by turbodan
Turbos utilize some of the heat energy that is wasted out the exhaust on NA and supercharged engines. That is the fundamental difference that gives the advantage. A well designed turbo system will have more intake manifold pressure than exhaust backpressure, so scavenging isn't a problem. You can also alter the pressure ratio between the intake and exhaust to suit your needs. Different pressure ratios can be used to fine tune cylinder filling.
The proof is on the dyno. I've seen a few engines running a supercharger and a turbocharger on the same engine at the same boost pressure. The turbo system always comes out ahead.
Posted: Oct 04, 2008 1:47 PM
by alijonny
I would rather hear a whistle over a whine! lol.