Manual

47
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 comp ensate the fuel for changes in inlet
air temperature and battery voltage, and also two correction M aps to adjust ignition timin g for
coolant and inlet air temp eratures.
WARN ING:
MOS T US ERS S HO ULD N EV ER AD J US T THES E MA PS . THES E
MAPS ARE FACTORY S ET TO PROVID E EXCELLENT
CORRECTION FOR ALMOST ALL ENGINES. THESE MAPS
SHOULD NOT BE ADJUSTED UNLESS THE USER HAS
EXPERIMENTALLY DERIVED DATA THAT THE CORRECTION
FACTORS COULD BE BETTER CUSTOMISED TO SUIT A
PARTICULAR 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 enterin g the in let manifold varies with the temp erature of the air. To
compensate for this, the F10 uses the Fuel Air Correction Map. 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 ap s and Set-up M enu. Across the
bottom of the map display ed is the inlet air temp erature. An arrow ap p ears showing which b ar
the system is currently using.
The map displayed is split by a horizontal line. Bars above this line indicate a positive
correction makin g 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 comp ensates 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 op en time. To comp ensate, the F10
applies the Battery Voltage M ap to increase the injector on-time as the vo ltage drop s. This
map should not be altered unless the system is connected to a fuel injector test bench that will