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Autoignition Threshold Theory

Autoignition Threshold Theory

Autoignition Threshold Theory

For a turbocharged engine:
What is the relationship between the knock threshold and air pressure?  My question is related to running the maximum amount of boost on pump gasoline.  I know that as air temperature increases, so does the tendency for engine knock.  Independent of temperature, does increased pressure lead to engine knock?  For example, say you are running a pressure ratio of 3:1, but it is intercooled down to ambient temperature, would the limiting factors for knock (ignition advance,compression ratio,ect) be the same as for a normally-aspirated engine?  Is there any data on this subject?  Thank you.

RE: Autoignition Threshold Theory

        Increased pressure, even if the temperature is constant, will make knock more likely.  I cannot point you to any specific data.  Some data is definitely out there in technical publications by organizations like SAE or the Combustion Institute.


RE: Autoignition Threshold Theory

I have been looking for information on this subject too - hard to find good data.  I'll dive into SAE and Combustion Institute soon.  For now, check out this page, *specifically the Max Reliable Boost Pressure vs Static Compression Ratio with respect to intercooling.

Note that this chart should vary greatly with response to engine specific combustion dynamics.

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