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Originally Posted by oil pan 4
Most blowers used in gasoline applications have a bypass valve built into them
Certain years of supercharged Toyota MR2 use a clutched supercharger. Toyota claimed that not spinning the blower when its not needed saved them 2mpg.
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So a turbocharger kind of selfregulates. Correct? I mean when you let off the accelerator there's less turning it, whereas a supercharger is completely RPM dependent. Would there be any advantage in bypassing the turbine with a turbo? Probably not, especially with a diesel.
Quote:
Originally Posted by oil pan 4
On a diesel you want air being forced into the engine all the time. That waste heat that goes out the exhaust is doing work via the turbocharger and force feeding more air into the engine.
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I've thought about that too. Usually when the exhaust valve opens there's still pressure in the cylinder that just escapes in a loud POP! So unless you have an atkins cycle engine that has a longer combustion stroke than it's compression stroke the only way to utilize that extra pressure would be to run another engine, such as a turbine. I've wondered if instead of runing a superchargering wheel off the turbine if it's possible to maybe run something else, like an alternator. But if more air=more efficiency then I guess I better figure out how to addapt a turbosupercharger (there! I said it!) to the engine.
Quote:
Originally Posted by oil pan 4
Diesel engines are not like gas engines, diesels need all the air they can possibly get all the time. This helps their fuel mile age and power. Completely opposite of how a gasoline engine is.
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Yes, in practice this is usually true of gasoline engines. However, I've found it very interesting to find that a gasoline's most efficient tune is full throttle, low RPMs and leaner than stoich. I'm not saying that's good for longevity but it's best for efficiency. But now I'm really derailing the thread. Sorry.
So, I think the piston oil squirters and forged pistons such won't be as necessary if I don't go to crazy with the fuel screw when I get a turbo on there. Just another question, right now the stock exhaust is really tiny. Looks like about an inch and a half diameter. I'm guessing with the turbine causing a restriction, plus more flow, I should think about enlarging the exhaust diameter. Right?