what gains from a tune?
09-27-2017, 10:30 PM
#21
Le Mans Master
Member Since: Aug 2005
Location: CA.
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St. Jude Donor '13-'14-'15
irrational, yes, i agree, but there are just so many threads stating 10% or more, on here and elsewhere. i saw somebody reporting a 60 hp gain, i believe, going from a low octane to a high octane tune. so is all the stuff made up (by the tuners and dyno operators) or im i missing some secrets? i mean, you can only adjust timing and fuel, right?
Basically your engine runs all the time in the HIGH OCT table
The ECM will count "occurrences of knock" when it reaches some unknown number of those occurrences the timing table will slip into the LOW OCT table----This is to compensate for a bad tank of gas or cheap gas ---The only way to get your ECM back into the HIGH OCT table is to run the tank empty and refill it full with some new better gas
Now most tuners to eliminate dropping into the LOW OCT table will copy and paste the HIGH table into the LOW table--This will prevent losing most of your timing Occurrences of Knock can be in audible and the knock sensors can pick up engine noises which they will interpret as knock when in fact there is none---New valve train rockers or larger springs -- aftermarket cams---LT headers all create new noises that the knock sensors "think" is knock however it isn't---
Tuners can tune out this FALSE KNOCK either by desensitizing the knock sensors OR copy and paste the HI table into the LOW to prevent unwanted timing removal
