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Old 11-21-2014, 03:02 PM   #39 (permalink)
ever_green
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Join Date: May 2011
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gueff - '19 Mercedes Benz A250 4MATIC AMG
90 day: 30.55 mpg (US)
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Quote:
Originally Posted by Daox View Post
If your header is creating more low end torque, wouldn't it make sense that it also creates more knock? Higher charge density = more knock, right?

Higher charge density at the same ignition timing should always mean better efficiency (assuming everything else is constant). However, if your engine must retard timing for a higher charge density, then you can obviously lower efficiency. It sounds like this is what is happening to you ever_green.
any non-detonating engine would make more power than a detonating one. plus sometimes its good to reduce VE a little to run more timing. hot rodders sometimes run less compression pistons to run more timing. there is a balance.

i did still get knock in closed loop at lower rpms...like 1600. this was addressed with slightly more closed loop fueling. it was not as horrid as stock where 10* of retard was needed.
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