Haltech F10 - Manual (Page 49)

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SECTION 2 Other Adjustable Features
CHAPTER 6 THROTTLE EFFECTS
6.1 Throttle Response
Where the procedures described in the previous chapter tune for constant load running, the
methods and features outlined in this section will improve the throttle response of your
engine.
The manifold pressure sensor used with the F10 is very fast. It can respond much faster than
is required to track any sudden changes in load on your engine. However the pressure seen at
the sensor input does not change as quickly as that in the manifold due to the length of the
connecting pipe and some other factors. The “lag” effect that occurs due to the connecting
pipe can be limited by keeping the pipe as short as possible.
Sudden throttle movements which result in sudden manifold pressure changes will result in
poor fuelling of the engine due to the pressure “lag” previously mentioned. This results in a
lean fuel-air mixture when the throttle is opened. Another problem which contributes to a
lean fuel-air mixture when the throttle is opened is the sudden change in pressure that forces
fuel out of atomisation and onto the manifold walls this fuel is not drawn into the cylinder
which results in a lean fuel-air mixture.
To overcome any lean fuel-air mixtures during sudden throttle movement, the Haltech system
uses a throttle accelerator pump function or “Throttle-pump”. This function delivers extra fuel
during sudden throttle movements. The effect of sudden throttle movements varies across
engine speed, the Throttle-Pump function offered in the F10 ECU allows for this.
6.1.1 Throttle-Pump software control
To access the Throttle-Pump page press Alt – O to open the Options menu then scroll to the
Throttle-Pump menu item and press enter.
Six single bars will appear on the screen. The two bars on the left are used when the engine
speed is below 1500 rpm. The two bars in the middle operate between 1500 and 3000 rpm and
the two bars on the right are used above 3000 rpm. These bars set the amount of extra fuel
that will be added to the current fuel value during a sudden change in throttle. This extra fuel
is added progressively as the throttle movement continues.
The increase bars determine how much extra fuel the engine gets when you open the throttle.
Once the throttle movement stops the extra fuel value decays at a rate set by the sustain bars.
The heights of the increase bars and the sustain bars are adjusted using the same keys that are
used for adjusting the fuel curve bars. The left and right arrow keys allow you to move from
one bar to the next.
The throttle pump values should be set up after the fuel and maps are correctly tuned for