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Old Jul 9, 2009, 01:10 PM   #2
LaXGSR
Evolving Member
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Join Date: Apr 2009
Location: US
Posts: 272

Drives: Evo X GSR

Quote:
Originally Posted by EVOXSILVER View Post
My car has bad knock (3 to 7 knock counts) from 6600 to 7800 rpms so i've decided to pull timing from my maps. I've noticed from the logs that my car is running on low octane timing map, why?
Are you sure it's running on the low octane timing map? Note that the ECU will make corrections based on knock, air temperature, altitude, etc. There are various compensations made by the ECU that would cause you to see lower timing than your high octane map (even with no knock present). If the ECU sees a lot of knock continuously, then the "octane level" will be dropped, causing it to interpolate between the high/low octane maps. Log octane level and see what is it at.
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