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      01-10-2008, 07:09 PM   #107
shiv@vishnu
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Drives: X1, 335i
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Quote:
Originally Posted by Malekreza11 View Post
what is the A/F ratio at 14ish PSI of boost? Considering the direct injection and 10.2 compression ratio of the motor makes it beneficial to make power and all, what is done about the ignition timing since it is not directly controlled? Is the knock prevented by the pro-cede unit by richening up the fuel mixture around peak torque, or is the stock knock control doing the work?
The PROcede actively retards the ignition timing under boost. Sometimes by as much as 6 degrees. This way the factory ECU does not need to respond through negative timing advance trims or knock-induced ignition retard events. Adding fuel to snuff out knock is reasonably ineffective in a DI system.

Shiv