Haltech F10 - Manual (Page 52)

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CHAPTER 8 CORRECTION FACTORS
Note: The following correction factors should not be altered unless you have a
detailed knowledge of your engine and the environment in which it operates.
Severe damage can be done to your engine if the correction factors are not set
properly.
The Haltech F10 has two further correction maps to compensate the fuel for changes in inlet
air temperature and battery voltage, and also two correction M aps to adjust ignition timing for
coolant and inlet air temperatures.
WARN ING:
MOST USERS SHOULD NEVER ADJUST THESE MAPS. THESE
MAPS ARE FACTORY SET TO PROVID E EXCELLENT
CORRECTION FOR ALMOST ALL ENGIN ES. THESE MAPS
SHOULD NOT BE ADJUSTED UNLESS THE USER HAS
EXPERIMENTALLY DERIVED DATA THAT THE CORRECTION
FACTORS COULD BE BETTER CUSTOMISED TO SUIT A
PARTIC ULAR ENGINE.
When the F10 software is run in the OFFLINE mode, the software will load factory-set
correction maps unless other maps are loaded.
8.1 Air Temp Fuel Map
The mass of air entering the inlet manifold varies with the temperature of the air. To
compensate for this, the F10 uses the Fuel Air Correction M ap. The values supplied in your
ECU have been mathematically determined to give the optimal correction for most engines.
The Fuel Air Correction M ap is accessed via the Fuel M aps and Set-up M enu. Across the
bottom of the map displayed is the inlet air temperature. An arrow appears showing which bar
the system is currently using.
The map displayed is split by a horizontal line. Bars above this line indicate a positive
correction making the mixture richer. Bars below the line indicate a negative correction
making the mixture leaner.
A typical Fuel Versus Air Temp M ap was loaded into your F10 at the factory. You should not
modify it unless you experience trouble with variation in engine performance with air
temperature.
8.2 The Battery Voltage Map
The Haltech F10 uses intelligent fuel injection driver circuitry that compensates for changes
in battery voltage. This compensation can be insufficient for the full range of battery voltages
that a vehicle's electrical system may experience. As the battery voltage falls, the injectors
will take longer to turn on and so reduce the effective open time. To compensate, the F10
applies the Battery Voltage M ap to increase the injector on-time as the voltage drops. This
map should not be altered unless the system is connected to a fuel injector test bench that will